diff --git a/dygraph/ppdet/engine/trainer.py b/dygraph/ppdet/engine/trainer.py
index 32aff4e2522fd9551b7bbd6c2bc339f5acc16330..20ea16b7a485d2e57b918996427ec7c37bc0b058 100644
--- a/dygraph/ppdet/engine/trainer.py
+++ b/dygraph/ppdet/engine/trainer.py
@@ -167,6 +167,8 @@ class Trainer(object):
 
         if self._nranks > 1:
             model = paddle.DataParallel(self.model)
+        else:
+            model = self.model
 
         self.status.update({
             'epoch_id': self.start_epoch,