diff --git a/fastNLP/core/_logger.py b/fastNLP/core/_logger.py
index 7f1f7df1..a881203e 100644
--- a/fastNLP/core/_logger.py
+++ b/fastNLP/core/_logger.py
@@ -145,7 +145,7 @@ def _init_logger(path=None, stdout='tqdm', level='INFO'):
     # logger = logging.getLogger()
     logger = logging.getLogger(ROOT_NAME)
     logger.propagate = False
-    logger.setLevel(level)
+    logger.setLevel(1)  # make the logger the lowest level
     
     _set_stdout_handler(logger, stdout, level)
     
@@ -168,4 +168,4 @@ def _get_logger(name=None, level='INFO'):
     return logger
 
 
-logger = _init_logger(path=None, level=1) # make the logger the lowest level
+logger = _init_logger(path=None, level='INFO')
diff --git a/test/core/test_logger.py b/test/core/test_logger.py
index 610f42bd..628ed94d 100644
--- a/test/core/test_logger.py
+++ b/test/core/test_logger.py
@@ -29,5 +29,6 @@ class TestLogger(unittest.TestCase):
     def test_stdout(self, mock_out):
         for i in range(3):
             logger.info(self.msg)
+            logger.debug('aabbc')
 
         self.assertEqual([self.msg for i in range(3)], mock_out.getvalue().strip().split('\n'))