diff --git a/video-gen-api/app/api/v1/payments.py b/video-gen-api/app/api/v1/payments.py
index 92c09466..490d2533 100644
--- a/video-gen-api/app/api/v1/payments.py
+++ b/video-gen-api/app/api/v1/payments.py
@@ -125,11 +125,13 @@ async def wechat_callback(request: Request, db: AsyncSession = Depends(get_db)):
         timestamp = headers.get("Wechatpay-Timestamp", "")
         nonce = headers.get("Wechatpay-Nonce", "")
         signature = headers.get("Wechatpay-Signature", "")
+        serial_no = headers.get("Wechatpay-Serial", "")
         
         # 验证签名：使用平台公钥验证
-        if public_key:
+        if public_key and serial_no:
             try:
-                # 使用 wechatpayv3.utils.rsa_verify 验证签名
+                # 构造签名串：timestamp + "\n" + nonce + "\n" + body + "\n"
+                # 符合微信支付官方文档规范：https://pay.weixin.qq.com/doc/v3/merchant/4013053249
                 is_verified = rsa_verify(
                     timestamp=timestamp,
                     nonce=nonce,
@@ -138,13 +140,17 @@ async def wechat_callback(request: Request, db: AsyncSession = Depends(get_db)):
                     public_key=load_public_key(public_key)
                 )
                 if not is_verified:
-                    logger.warning("WeChat callback signature verification failed")
+                    logger.warning(f"WeChat callback signature verification failed: serial={serial_no}")
                     raise HTTPException(status_code=400, detail="签名验证失败")
+                logger.debug(f"WeChat callback signature verified: serial={serial_no}")
             except Exception as e:
-                logger.warning(f"WeChat signature verification error: {e}")
+                logger.warning(f"WeChat signature verification error: {e}, serial={serial_no}")
                 raise HTTPException(status_code=400, detail="签名验证失败")
         else:
-            logger.warning("WeChat platform public key not configured, skipping signature verification")
+            if not public_key:
+                logger.warning("WeChat platform public key not configured, skipping signature verification")
+            if not serial_no:
+                logger.warning("Wechatpay-Serial header missing, skipping signature verification")
         
         # 解密回调数据：使用 API v3 key
         import json