diff --git a/app/main.py b/app/main.py
index afc1f50..61a8dd7 100644
--- a/app/main.py
+++ b/app/main.py
@@ -47,6 +47,13 @@ async def lifespan(app: FastAPI):
     yield
     if db is not None and db._owns_session:
         await db.close()
+        # 释放引擎连接池，避免连接残留导致下次启动 initialize() 被锁挂起/连接泄漏
+        engine = getattr(db, "_engine", None)
+        if engine is not None:
+            try:
+                await engine.dispose()
+            except Exception:  # noqa: BLE001
+                pass
 
 
 app = FastAPI(