diff --git a/hts/OrderChecker.py b/hts/OrderChecker.py
index ad86ca9..9a95bdb 100644
--- a/hts/OrderChecker.py
+++ b/hts/OrderChecker.py
@@ -30,7 +30,8 @@ class OrderChecker:
         return
 
     def exist(self, stock_code):
-        if self.order_df.loc[self.order_df["stock_code"] == stock_code] is None:
+        tmp = self.order_df.loc[self.order_df["stock_code"] == stock_code]
+        if tmp is None or len(tmp) == 0:
             return False
         return True