diff --git a/backend/app/api/bsc_layers.py b/backend/app/api/bsc_layers.py
index 929b27f7..2468eb9e 100644
--- a/backend/app/api/bsc_layers.py
+++ b/backend/app/api/bsc_layers.py
@@ -4,6 +4,7 @@ from sqlalchemy.orm import Session
 from typing import List
 
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_auth
 from app.models import BscLayerConfig, Entity
 
@@ -13,7 +14,7 @@ router = APIRouter(prefix="/api/cma/bsc-layers", tags=["BSC层配置"],
 
 
 @router.get("")
-def list_bsc_layers(entity_id: int = Query(1, description="企业ID"), db: Session = Depends(get_db)):
+def list_bsc_layers(entity_id: int = Depends(get_entity_id), db: Session = Depends(get_db)):
     """获取某企业的BSC四层权重配置"""
     # 验证企业存在
     entity = db.query(Entity).filter(Entity.id == entity_id).first()
diff --git a/backend/app/api/cash.py b/backend/app/api/cash.py
index 6dab3ef4..18c7ad7e 100644
--- a/backend/app/api/cash.py
+++ b/backend/app/api/cash.py
@@ -4,6 +4,7 @@ from datetime import datetime, timedelta
 from fastapi import APIRouter, HTTPException, Depends, Query
 from sqlalchemy.orm import Session
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_role
 from app.models import CashPlan
 from app.utils.cash_forecast_engine import (
@@ -45,7 +46,7 @@ def _plan_dict(p: CashPlan) -> dict:
 
 @router.get("/gap-forecast")
 def api_gap_forecast(
-    entity_id: int = Query(1, description="企业ID"),
+    entity_id: int = Depends(get_entity_id),
     days: int = Query(30, ge=1, le=90, description="预测天数"),
     current_cash: float = Query(None, description="当前现金余额(万元)，不传则自动获取"),
     db: Session = Depends(get_db),
@@ -60,7 +61,7 @@ def api_gap_forecast(
 
 @router.get("/balance")
 def api_get_balance(
-    entity_id: int = Query(1),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
 ):
     """获取当前现金余额（预测基线）"""
@@ -89,7 +90,7 @@ def api_set_balance(
 
 @router.get("/plans")
 def api_list_plans(
-    entity_id: int = Query(1),
+    entity_id: int = Depends(get_entity_id),
     plan_type: str = Query(None, description="receive/pay"),
     status: str = Query(None, description="pending/completed/cancelled"),
     month: str = Query(None, description="YYYY-MM 按计划月份过滤"),
@@ -215,7 +216,7 @@ def api_complete_plan(plan_id: int, db: Session = Depends(get_db)):
 
 @router.get("/upcoming")
 def api_upcoming(
-    entity_id: int = Query(1),
+    entity_id: int = Depends(get_entity_id),
     days: int = Query(7, ge=1, le=30),
     db: Session = Depends(get_db),
 ):
@@ -243,7 +244,7 @@ def api_upcoming(
 
 @router.get("/dashboard")
 def api_cash_dashboard(
-    entity_id: int = Query(1),
+    entity_id: int = Depends(get_entity_id),
     month: str = Query(None, description="YYYY-MM 默认本月"),
     days: int = Query(30),
     current_cash: float = Query(None, description="当前现金余额(万元)"),
@@ -303,7 +304,7 @@ def api_cash_dashboard(
 # ══════════════════════════════════════════════════════════
 
 @router.post("/check-alerts")
-def api_check_cash_alerts(entity_id: int = 1, db: Session = Depends(get_db)):
+def api_check_cash_alerts(entity_id: int = Depends(get_entity_id), db: Session = Depends(get_db)):
     """手动触发资金预警检查（写入预警中心kpi_alerts）"""
     try:
         return check_cash_alerts(db, entity_id=entity_id)
@@ -313,7 +314,7 @@ def api_check_cash_alerts(entity_id: int = 1, db: Session = Depends(get_db)):
 
 
 @router.get("/alerts/status")
-def api_cash_alert_status(entity_id: int = Query(1), db: Session = Depends(get_db)):
+def api_cash_alert_status(entity_id: int = Depends(get_entity_id), db: Session = Depends(get_db)):
     """资金预警状态概览 — 当前缺口/逾期情况（不写库，只读）"""
     result = forecast_cash_flow_with_plans(entity_id, db, days=30)
     return {
diff --git a/backend/app/api/data.py b/backend/app/api/data.py
index 7c589d6b..e8efdfd7 100644
--- a/backend/app/api/data.py
+++ b/backend/app/api/data.py
@@ -7,6 +7,7 @@ from sqlalchemy.orm import Session
 from sqlalchemy import func
 from typing import Optional
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_auth, require_role
 from app.models import KPIValue, DataSourceConfig, OperationLog, KPIDefinition
 
@@ -165,7 +166,7 @@ def _smart_detect_statement_type(filename: str) -> str | None:
 @router.post("/import-excel-smart")
 async def import_excel_smart(
     file: UploadFile = File(...),
-    entity_id: int = Form(1),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
 ):
     """智能导入 — BOT自动识别列名/期间/报表类型，无需手动映射"""
diff --git a/backend/app/api/growth_quality.py b/backend/app/api/growth_quality.py
index 5a27c684..5c94fdfa 100644
--- a/backend/app/api/growth_quality.py
+++ b/backend/app/api/growth_quality.py
@@ -11,6 +11,7 @@ from datetime import datetime
 import re
 
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_auth, require_role
 from app.models import KPIDefinition, KPIValue, Entity
 
@@ -453,7 +454,7 @@ def _diagnose(db: Session, entity_id: int, period: str, history: List[dict]):
 
 
 @router.get("/periods")
-def list_periods(entity_id: int = Query(1), db: Session = Depends(get_db)):
+def list_periods(entity_id: int = Depends(get_entity_id), db: Session = Depends(get_db)):
     """列出某实体有KPI数据的期间（按月，含数据覆盖度，用于前端默认期间选择）"""
     rows = (db.query(KPIValue.period, KPIValue.kpi_id)
             .join(KPIDefinition, KPIDefinition.id == KPIValue.kpi_id)
@@ -470,7 +471,7 @@ def list_periods(entity_id: int = Query(1), db: Session = Depends(get_db)):
 
 @router.get("/diagnosis")
 def growth_quality_diagnosis(
-    entity_id: int = Query(1, ge=1),
+    entity_id: int = Depends(get_entity_id),
     period: Optional[str] = Query(None, description="期间 YYYY-MM，默认最近有数据期间"),
     db: Session = Depends(get_db),
 ):
diff --git a/backend/app/api/kpis.py b/backend/app/api/kpis.py
index ace05c5d..0bb6b3ed 100644
--- a/backend/app/api/kpis.py
+++ b/backend/app/api/kpis.py
@@ -7,6 +7,7 @@ from datetime import datetime
 import json
 
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_auth, require_role, filter_kpis_by_role, kpi_visible_dims
 from app.models import StrategicMap, MapObjective, KPIDefinition, KPIValue, KPIAlert, OperationLog, Entity, KPICausality, KPIHierarchy
 from app.api.kpi_governance import validate_kpi_payload, kpi_issues_message
@@ -27,7 +28,7 @@ def list_kpis(
     keyword: Optional[str] = None,
     epic: Optional[str] = None,
     category: Optional[str] = None,
-    entity_id: Optional[int] = None,
+    entity_id: int = Depends(get_entity_id),
     kpi_level: Optional[str] = None,
     db: Session = Depends(get_db),
     current_user = Depends(require_auth),
@@ -141,7 +142,7 @@ def _calc_five_tier_score(current_value, target_value, is_reverse=False):
 
 @router.get("/score")
 def get_kpi_score(
-    entity_id: int = Query(1, ge=1),
+    entity_id: int = Depends(get_entity_id),
     period: Optional[str] = None,
     db: Session = Depends(get_db),
     current_user = Depends(require_auth),
@@ -243,7 +244,7 @@ def get_kpi_score(
 
 @router.get("/glossary")
 def get_kpi_glossary(
-    entity_id: int = Query(1, ge=1),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     current_user = Depends(require_auth),
 ):
@@ -314,7 +315,7 @@ def get_kpi_glossary(
 
 @router.get("/hierarchy")
 def get_kpi_hierarchy(
-    entity_id: int = Query(1, ge=1),
+    entity_id: int = Depends(get_entity_id),
     kpi_id: Optional[int] = None,
     db: Session = Depends(get_db),
     current_user = Depends(require_auth),
diff --git a/backend/app/api/predict.py b/backend/app/api/predict.py
index 3940b51e..7b130b22 100644
--- a/backend/app/api/predict.py
+++ b/backend/app/api/predict.py
@@ -10,6 +10,7 @@ from app.utils.cash_forecast_engine import (
     calculate_accuracy, generate_scenario_suggestion,
 )
 from app.database import get_db
+from app.deps import get_entity_id
 from sqlalchemy.orm import Session
 
 logger = logging.getLogger("cma.predict")
@@ -183,7 +184,7 @@ def api_cash_forecast(data: dict, db: Session = Depends(get_db)):
 
 @router.get("/cash-forecast/history")
 def api_cash_forecast_history(
-    entity_id: int = 1,
+    entity_id: int = Depends(get_entity_id),
     days: int = 30,
     db: Session = Depends(get_db),
 ):
@@ -206,7 +207,7 @@ def api_cash_forecast_history(
 
 @router.get("/accuracy")
 def api_forecast_accuracy(
-    entity_id: int = 1,
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
 ):
     """预测准确率报表 — 上期预测 vs 本期实际"""
diff --git a/backend/app/api/tax_compliance.py b/backend/app/api/tax_compliance.py
index e4d9d8a4..94af03cf 100644
--- a/backend/app/api/tax_compliance.py
+++ b/backend/app/api/tax_compliance.py
@@ -11,6 +11,7 @@ from fastapi import APIRouter, Depends, HTTPException, Query
 from sqlalchemy.orm import Session
 
 from app.database import get_db
+from app.deps import get_entity_id
 from app.auth_middleware import require_auth, require_role
 from app.models import TaxRecord, InvoiceCheck, SocialSecurity, ExpenseReimbursement
 
@@ -140,7 +141,7 @@ def _apply_burden_to_all(db: Session, entity_id: int):
 def list_tax_records(
     period: str = Query(None),
     tax_type: str = Query(None),
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
 ):
@@ -236,7 +237,7 @@ def delete_tax_record(
 
 @router.get("/burden")
 def burden_analysis(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     tax_type: str = Query(None),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
@@ -274,7 +275,7 @@ def burden_analysis(
 
 @router.post("/check")
 def run_tax_check(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_role("ceo", "finance")),
 ):
@@ -358,7 +359,7 @@ def _check_invoice(db: Session, inv: InvoiceCheck):
 def list_invoices(
     status: str = Query(None),
     keyword: str = Query(None),
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
 ):
@@ -457,7 +458,7 @@ def delete_invoice(
 @router.post("/invoices/check")
 def batch_check_invoices(
     invoice_id: int = Query(None),
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_role("ceo", "finance")),
 ):
@@ -481,7 +482,7 @@ def batch_check_invoices(
 
 @router.get("/invoices/abnormal")
 def list_abnormal_invoices(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     limit: int = Query(50),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
@@ -556,7 +557,7 @@ def list_ss_records(
     period: str = Query(None),
     employee: str = Query(None),
     status: str = Query(None),
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
 ):
@@ -652,7 +653,7 @@ def delete_ss_record(
 
 @router.post("/ss/check")
 def batch_check_ss(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_role("ceo", "finance")),
 ):
@@ -674,7 +675,7 @@ def batch_check_ss(
 
 @router.get("/ss/abnormal")
 def list_abnormal_ss(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     limit: int = Query(50),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
@@ -693,7 +694,7 @@ def list_abnormal_ss(
 
 @router.get("/dashboard")
 def tax_dashboard(
-    entity_id: int = Query(None),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_auth),
 ):
@@ -771,7 +772,7 @@ def tax_dashboard(
 
 @router.post("/demo-data")
 def seed_demo_data(
-    entity_id: int = Query(1),
+    entity_id: int = Depends(get_entity_id),
     db: Session = Depends(get_db),
     _=Depends(require_role("ceo", "finance")),
 ):
diff --git a/frontend/src/api/index.ts b/frontend/src/api/index.ts
index daad802f..bd9b7da4 100644
--- a/frontend/src/api/index.ts
+++ b/frontend/src/api/index.ts
@@ -8,12 +8,7 @@ const api = axios.create({
 api.interceptors.request.use((config) => {
   const token = localStorage.getItem('cma_token')
   if (token) config.headers.Authorization = `Bearer ${token}`
-  // 多租户实时切换：统一附加当前企业ID（解决29个页面未传entity_id的问题）
-  const entityId = Number(localStorage.getItem('cma_entity_id') || 1)
-  config.headers['X-Entity-Id'] = String(entityId)
-  if (config.method === 'get' || config.method === 'GET') {
-    config.params = { ...(config.params || {}), entity_id: entityId }
-  }
+  // 账套模式：entity_id 由 token 绑定，前端不再自动附加 X-Entity-Id / entity_id
   return config
 })
 
@@ -32,6 +27,9 @@ api.interceptors.response.use(
 export const authApi = {
   login: (data: any) => api.post('/auth/login', data),
   register: (data: any) => api.post('/auth/register', data),
+  switchEntity: (data: any) => api.post('/auth/switch-entity', data),
+  myEntities: () => api.get('/auth/my-entities'),
+  loginEntities: (username: string) => api.get('/auth/login-entities', { params: { username } }),
 }
 
 export const kpiApi = {
diff --git a/frontend/src/layouts/MainLayout.vue b/frontend/src/layouts/MainLayout.vue
index 13dd33ca..3328cec8 100644
--- a/frontend/src/layouts/MainLayout.vue
+++ b/frontend/src/layouts/MainLayout.vue
@@ -48,6 +48,7 @@
 <script setup lang="ts">
 import { ref, computed, onMounted } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
+import { ElMessage } from 'element-plus'
 import api from '../api/index'
 import {
   User, Monitor, Document, TrendCharts, WarningFilled, Connection,
@@ -61,25 +62,35 @@ const router = useRouter()
 const isCollapse = ref(false)
 const mobileMenuOpen = ref(false)
 
-// ── 全局企业切换 ──
+// ── 全局企业切换（账套模式：switch-entity 重新签发token + 整页刷新） ──
 const entities = ref<any[]>([])
 const currentEntityId = ref(Number(localStorage.getItem('cma_entity_id') || 1))
 const currentEntityName = ref(localStorage.getItem('cma_entity_name') || '酣客')
-function onEntityChange(id: number) {
-  currentEntityId.value = id
-  const e = entities.value.find((x: any) => x.id === id)
-  currentEntityName.value = e?.short_name || e?.name || ''
-  localStorage.setItem('cma_entity_id', String(id))
-  localStorage.setItem('cma_entity_name', currentEntityName.value)
-  // 多租户联动：通知后端记录当前tenant（供项目Bot A2A分发）
+async function onEntityChange(id: number) {
+  if (id === Number(localStorage.getItem('cma_entity_id'))) return
   try {
-    api.post('/tenant/switch', { entity_id: id, source: 'cma-frontend' })
-  } catch (_) {}
-  location.reload()
+    const r: any = await api.post('/auth/switch-entity', {
+      entity_id: id,
+      from_entity_id: Number(localStorage.getItem('cma_entity_id') || 1),
+    })
+    localStorage.setItem('cma_token', r.token)
+    localStorage.setItem('cma_entity_id', String(r.entity_id))
+    localStorage.setItem('cma_entity_name', r.entity_short_name || r.entity_name || '')
+    // 多租户联动：通知后端记录当前tenant（供项目Bot A2A分发）
+    try {
+      api.post('/tenant/switch', { entity_id: r.entity_id, source: 'cma-frontend' })
+    } catch (_) {}
+    location.reload()
+  } catch (e: any) {
+    currentEntityId.value = Number(localStorage.getItem('cma_entity_id') || 1)
+    const msg = e?.response?.data?.detail || '切换失败'
+    ElMessage.error(msg)
+  }
 }
 onMounted(async () => {
+  // 账套模式：切换器只显示当前用户被授权的企业
   try {
-    const r: any = await api.get('/entities')
+    const r: any = await api.get('/auth/my-entities')
     entities.value = r.data || r || []
   } catch (_) {}
 })
diff --git a/frontend/src/views/Login.vue b/frontend/src/views/Login.vue
index 5ae77ee1..e7de1dc6 100644
--- a/frontend/src/views/Login.vue
+++ b/frontend/src/views/Login.vue
@@ -4,7 +4,17 @@
       <h1>管理会计OS</h1>
       <p class="subtitle">博海网络科技</p>
       <el-form ref="formRef" :model="form" label-width="0" @keyup.enter="handleLogin">
-        <el-form-item><el-input v-model="form.username" placeholder="用户名" size="large" /></el-form-item>
+        <el-form-item>
+          <el-input v-model="form.username" placeholder="用户名" size="large" @input="onUsernameChange" />
+        </el-form-item>
+        <el-form-item>
+          <el-select v-model="form.entity_id" placeholder="选择登录公司" size="large" style="width:100%" :disabled="entities.length === 0">
+            <el-option v-for="e in entities" :key="e.id" :label="e.short_name || e.name" :value="e.id">
+              <span>{{ e.short_name || e.name }}</span>
+              <span style="float:right;color:#999;font-size:12px;">{{ e.name }}</span>
+            </el-option>
+          </el-select>
+        </el-form-item>
         <el-form-item><el-input v-model="form.password" type="password" placeholder="密码" size="large" show-password /></el-form-item>
         <el-form-item><el-button type="primary" size="large" style="width:100%" :loading="loading" @click="handleLogin">登 录</el-button></el-form-item>
       </el-form>
@@ -13,27 +23,53 @@
 </template>
 
 <script setup lang="ts">
-import { ref, reactive } from 'vue'
+import { ref, reactive, onMounted } from 'vue'
 import { useRouter } from 'vue-router'
 import { ElMessage } from 'element-plus'
 import { authApi } from '../api/index'
 
 const router = useRouter()
 const loading = ref(false)
-const form = reactive({ username: 'admin', password: 'admin123' })
+const entities = ref<any[]>([])
+const form = reactive({ username: 'admin', password: 'admin123', entity_id: undefined as number | undefined })
+
+async function loadEntities(username: string) {
+  try {
+    const r: any = await authApi.loginEntities(username)
+    entities.value = r.data || []
+    // 默认选中第一个授权企业
+    if (entities.value.length > 0 && (form.entity_id === undefined || !entities.value.some((e: any) => e.id === form.entity_id))) {
+      form.entity_id = entities.value[0].id
+    }
+  } catch (_) {
+    entities.value = []
+  }
+}
+
+function onUsernameChange(val: string) {
+  if (val && val.trim()) loadEntities(val.trim())
+}
 
 async function handleLogin() {
+  if (form.entity_id === undefined) {
+    ElMessage.warning('请选择登录公司')
+    return
+  }
   loading.value = true
   try {
-    const res: any = await authApi.login(form)
+    const res: any = await authApi.login({ ...form, entity_id: Number(form.entity_id) })
     localStorage.setItem('cma_token', res.token)
     localStorage.setItem('cma_user', JSON.stringify(res.user))
+    localStorage.setItem('cma_entity_id', String(res.user?.entity_id ?? 1))
+    localStorage.setItem('cma_entity_name', res.user?.entity_short_name || res.user?.entity_name || '')
     router.push('/dashboard')
   } catch (e: any) {
     ElMessage.error(e?.response?.data?.detail || '登录失败')
   }
   loading.value = false
 }
+
+onMounted(() => loadEntities(form.username))
 </script>
 
 <style scoped>
diff --git a/frontend/src/views/ReportCenter.vue b/frontend/src/views/ReportCenter.vue
index 7979f40b..e22f128b 100644
--- a/frontend/src/views/ReportCenter.vue
+++ b/frontend/src/views/ReportCenter.vue
@@ -587,7 +587,7 @@ function getEntityId() {
 
 async function loadEntities() {
   try {
-    const r: any = await api.get('/entities')
+    const r: any = await api.get('/auth/my-entities')
     entities.value = r.data || r || []
     const e = entities.value.find((x: any) => x.id === currentEntityId.value)
     if (e) localStorage.setItem('cma_entity_name', e.short_name || e.name || '')
@@ -596,13 +596,19 @@ async function loadEntities() {
   }
 }
 
-function onEntityChange(id: number) {
-  localStorage.setItem('cma_entity_id', String(id))
-  const e = entities.value.find((x: any) => x.id === id)
-  if (e) localStorage.setItem('cma_entity_name', e.short_name || e.name || '')
-  ElMessage.success(`已切换企业：${e ? e.short_name + ' / ' + e.name : id}`)
-  loadAll()
-  loadStatutory()
+async function onEntityChange(id: number) {
+  // 账套模式：切换走 switch-entity 重新签发token + 整页刷新
+  if (id === Number(localStorage.getItem('cma_entity_id'))) return
+  try {
+    const r: any = await api.post('/auth/switch-entity', { entity_id: id })
+    localStorage.setItem('cma_token', r.token)
+    localStorage.setItem('cma_entity_id', String(r.entity_id))
+    localStorage.setItem('cma_entity_name', r.entity_short_name || r.entity_name || '')
+    ElMessage.success(`已切换企业：${r.entity_short_name || r.entity_name || id}`)
+    location.reload()
+  } catch (e: any) {
+    ElMessage.error(e?.response?.data?.detail || '切换失败')
+  }
 }
 
 // 跨页面同步：其他页面切换企业时联动刷新