diff --git a/login_manager.py b/login_manager.py
index 81c5d65..be15142 100644
--- a/login_manager.py
+++ b/login_manager.py
@@ -96,11 +96,19 @@ class login_manager:
             login_manager.logger.info('logout_state: %s', 'success' if html_title == '信息页' else 'fail')
 
 
+def load_auth_info(path: str):
+    with open(path, 'r', encoding='utf-8') as file:
+        username = file.readline().strip()
+        password = file.readline().strip()
+        return username, password
+
 def main():
     logging.basicConfig(level=logging.INFO)
     logger = logging.getLogger('main')
 
-    parser = argparse.ArgumentParser(description='login or logout bistu wifi')
+    parser = argparse.ArgumentParser()
+    parser.description = 'login or logout bistu wifi'
+    parser.epilog = 'the config file format(without quote): "{username}\\n{password}". The "\\n" is a newline charactor'
 
     parser.add_argument('username', nargs='?',
                         type=str, help='username you use to login bistu wifi, logout if not provided')
@@ -108,6 +116,8 @@ def main():
                         type=str, help='password you use to login bistu wifi, logout if not provided')
     parser.add_argument('-o', '--logout', nargs='?', type=bool,
                         help='logout bistu wifi')
+    parser.add_argument('-c', '--config', nargs='?', type=str,
+                        help='load username and password from config file')
 
     args = parser.parse_args()
     
@@ -115,11 +125,17 @@ def main():
     logger.debug('parse argument: password= %s', args.password)
     logger.debug('parse argument: logout= %s', args.logout)
 
-    if args.username is None or args.password is None or args.logout:
-        login_manager.logout()
-    else:
+    if args.config is not None:
+        username, password = load_auth_info(args.config)
+        manager = login_manager(username, password)
+        manager.login()
+    elif args.username is not None and args.password is not None:
         manager = login_manager(args.username, args.password)
         manager.login()
+    elif args.logout:
+        login_manager.logout()
+    else:
+        parser.print_help()
 
 
 if __name__ == '__main__':