diff --git a/accounts/es_client.py b/accounts/es_client.py
index 50f7c6f..a13ce71 100644
--- a/accounts/es_client.py
+++ b/accounts/es_client.py
@@ -2,10 +2,8 @@ import base64
 from elastic.es_connect import get_user_by_username as es_get_user_by_username
 from .crypto import salt_for_username, derive_password
 
-
 def get_user_by_username(username: str):
     """
-    从Elasticsearch获取用户数据；若不存在则回退到内置admin。
     期望ES中存储的是明文密码，登录时按用户名盐派生后对nonce做HMAC验证。
     """
     es_user = es_get_user_by_username(username)
@@ -18,12 +16,4 @@ def get_user_by_username(username: str):
             'password': base64.b64encode(derived).decode('ascii'),
             'permission': es_user.get('permission', 1),
         }
-
-    salt = salt_for_username('admin')
-    derived = derive_password('admin', salt)
-    return {
-        'user_id': 0,
-        'username': 'admin',
-        'password': base64.b64encode(derived).decode('ascii'),
-        'permission': 0,
-    }
\ No newline at end of file
+    return None
\ No newline at end of file