diff --git a/gateway/scripts/ocg_router.py b/gateway/scripts/ocg_router.py
index c8680c4..78337ea 100644
--- a/gateway/scripts/ocg_router.py
+++ b/gateway/scripts/ocg_router.py
@@ -584,8 +584,19 @@ class RouterHandler(BaseHTTPRequestHandler):
                     err_body = resp.read().decode("utf-8", errors="replace")[:500]
                     return {"ok": False, "status": status, "error": f"HTTP {status}: {err_body}"}
 
-                # 透传响应
+                # 透传响应 + 空输出检测（2026-08-14 老莫：空输出自动换 key）
                 resp_body = resp.read()
+                if not is_stream:
+                    # 非流式：解析 JSON 检测空输出
+                    try:
+                        import json as _json
+                        d = _json.loads(resp_body.decode("utf-8", errors="replace"))
+                        content = d.get("choices", [{}])[0].get("message", {}).get("content", "")
+                        if not content or not str(content).strip():
+                            log.warning("empty content detected via key, retrying next key")
+                            return {"ok": False, "status": 0, "error": "empty_content"}
+                    except Exception:
+                        pass  # 解析失败不阻断（正常透传）
                 self._send_response(status, dict(resp.headers), resp_body)
                 return {"ok": True}