diff --git a/src/connector/python/linux/python3/taos/cinterface.py b/src/connector/python/linux/python3/taos/cinterface.py
index c9d0551af5faedc0b9726fa9be28337f26bba079..7b8e9b08972e46c591f4525f57d39404996a56d1 100644
--- a/src/connector/python/linux/python3/taos/cinterface.py
+++ b/src/connector/python/linux/python3/taos/cinterface.py
@@ -225,6 +225,7 @@ class CTaosInterface(object):
 
         if connection.value == None:
             print('connect to TDengine failed')
+            raise ConnectionError("connect to TDengine failed")
             # sys.exit(1)
         #else:
         #    print('connect to TDengine success')