diff --git a/backend/app/services/wecom_bot.py b/backend/app/services/wecom_bot.py
index a739cb8..d43837a 100644
--- a/backend/app/services/wecom_bot.py
+++ b/backend/app/services/wecom_bot.py
@@ -1,6 +1,6 @@
 import logging
-
-import httpx
+import json
+from urllib import request
 
 from app.core.config import settings
 
@@ -13,13 +13,16 @@ def send_wecom_text(content: str) -> bool:
     if not text or not webhook:
         return False
     try:
-        response = httpx.post(
+        payload = json.dumps({"msgtype": "text", "text": {"content": text[:3500]}}).encode("utf-8")
+        req = request.Request(
             webhook,
-            json={"msgtype": "text", "text": {"content": text[:3500]}},
-            timeout=10.0,
+            data=payload,
+            headers={"Content-Type": "application/json"},
+            method="POST",
         )
-        response.raise_for_status()
-        data = response.json()
+        with request.urlopen(req, timeout=10) as resp:
+            body = resp.read().decode("utf-8", errors="ignore")
+        data = json.loads(body or "{}")
         ok = int(data.get("errcode", -1)) == 0
         if not ok:
             logger.warning(f"WeCom bot send failed: {data}")