diff --git a/vnpy/trader/utility.py b/vnpy/trader/utility.py
index bdd3f93d..1843b31f 100644
--- a/vnpy/trader/utility.py
+++ b/vnpy/trader/utility.py
@@ -253,6 +253,9 @@ class BarGenerator:
         """
         Generate the bar data and call callback immediately.
         """
+        self.bar.datetime = self.bar.datetime.replace(
+            second=0, microsecond=0
+        )
         self.on_bar(self.bar)
         self.bar = None