diff --git a/src/connector/python/linux/python2/taos/cinterface.py b/src/connector/python/linux/python2/taos/cinterface.py
index c26e5c0967918bd45f362b3df6267561e80dfd66..32859f6b340b4393b523d475bce1ac89cef1a040 100644
--- a/src/connector/python/linux/python2/taos/cinterface.py
+++ b/src/connector/python/linux/python2/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')