diff --git a/packages/application/viral_video/prompt_loader.py b/packages/application/viral_video/prompt_loader.py
index 32af8898c..611f5f709 100644
--- a/packages/application/viral_video/prompt_loader.py
+++ b/packages/application/viral_video/prompt_loader.py
@@ -50,12 +50,39 @@ def _fallback(prompt_type: str) -> Optional[PromptTemplate]:
     return None
 
 
-def _load_from_db(prompt_type: str) -> Optional[PromptTemplate]:
-    if _session_mod.SessionLocal is None:
+_lazy_session = None
+
+
+def _get_session():
+    """优先用全局 SessionLocal（worker）；否则按应用配置懒建同步引擎（api）。"""
+    global _lazy_session
+    if _session_mod.SessionLocal is not None:
+        return _session_mod.SessionLocal()
+    if _lazy_session is not None:
+        return _lazy_session()
+    try:
+        from packages.config import get_shared_settings
+
+        url = str(get_shared_settings().database_url)
+    except Exception:  # noqa: BLE001
         return None
+    if not url:
+        return None
+    url = url.replace("postgresql+asyncpg://", "postgresql+psycopg://")
+    url = url.replace("postgresql://", "postgresql+psycopg://") if url.startswith("postgresql://") else url
+    engine = sa.create_engine(url, pool_pre_ping=True, pool_size=2, max_overflow=2)
+    from sqlalchemy.orm import sessionmaker
+
+    _lazy_session = sessionmaker(bind=engine)
+    return _lazy_session()
+
+
+def _load_from_db(prompt_type: str) -> Optional[PromptTemplate]:
     session = None
     try:
-        session = _session_mod.SessionLocal()
+        session = _get_session()
+        if session is None:
+            return None
         sql = sa.text("""
             SELECT name, prompt_type, version, system_prompt,
                    user_prompt_template, COALESCE(example_output, '') AS example_output,