diff --git a/backend/app/utils/cash_forecast_engine.py b/backend/app/utils/cash_forecast_engine.py
index 7483c9bc..b72fbd69 100644
--- a/backend/app/utils/cash_forecast_engine.py
+++ b/backend/app/utils/cash_forecast_engine.py
@@ -680,7 +680,21 @@ def check_cash_alerts(db: Session, entity_id: int = 1) -> dict:
             days_late = (today - p.plan_date).days
             msg = (f"【到期未收款】应收款{p.counterparty or '客户'} {p.amount:.1f}万 "
                    f"原计划{p.plan_date.strftime('%Y-%m-%d')}到期，已逾期{days_late}天未收回")
-            if _exists(msg):
+            # 2026-08-30修复: 按plan_id去重（消息含"已逾期X天"动态文本，全文匹配会每天生成重复预警）
+            existing_plan_alert = db.query(KPIAlert).filter(
+                KPIAlert.alert_type == "cash_plan",
+                KPIAlert.status.in_(["pending", "processing"]),
+            ).all()
+            dup = False
+            for ea in existing_plan_alert:
+                try:
+                    es = _json.loads(ea.suggestion) if ea.suggestion else {}
+                    if isinstance(es, dict) and es.get("plan_id") == p.id:
+                        dup = True
+                        break
+                except Exception:
+                    continue
+            if dup:
                 continue
             alert = KPIAlert(
                 kpi_id=ar_kpi.id,