diff --git a/nebula3/gclient/net/Connection.py b/nebula3/gclient/net/Connection.py
index a8eaa8e8..897bb334 100644
--- a/nebula3/gclient/net/Connection.py
+++ b/nebula3/gclient/net/Connection.py
@@ -171,6 +171,7 @@ def authenticate(self, user_name, password):
         try:
             resp = self._connection.authenticate(user_name, password)
             if resp.error_code != ErrorCode.SUCCEEDED:
+                self._connection.is_used = False
                 raise AuthFailedException(resp.error_msg)
             return AuthResult(
                 resp.session_id, resp.time_zone_offset_seconds, resp.time_zone_name