diff --git a/deploy.sh b/deploy.sh
index 9f7fda77..e0353540 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -28,9 +28,13 @@ echo "    ✓ 部署完成"
 # 3. 更新后端依赖
 echo "[3/4] 更新后端..."
 cd "$SCRIPT_DIR/backend"
-source venv/bin/activate
-pip install -r requirements.txt --quiet --no-cache-dir
-deactivate
+if [ -f venv/bin/activate ]; then
+  source venv/bin/activate
+  pip install -r requirements.txt --quiet --no-cache-dir
+  deactivate
+else
+  venv/bin/pip3 install -r requirements.txt --quiet --no-cache-dir || venv/bin/pip install -r requirements.txt --quiet --no-cache-dir
+fi
 echo "    ✓ 依赖更新完成"
 
 # 4. 重启后端服务