diff --git a/ppdet/engine/trainer.py b/ppdet/engine/trainer.py
index cef560d9d3cadf923fd0683ba5996a541be8fd65..e0ac8ea16bbc3cb0728e05e741eb53c0e980bdae 100644
--- a/ppdet/engine/trainer.py
+++ b/ppdet/engine/trainer.py
@@ -17,6 +17,8 @@ from __future__ import division
 from __future__ import print_function
 
 import os
+import sys
+import copy
 import time
 import random
 import datetime
@@ -326,7 +328,7 @@ class Trainer(object):
 
             # apply ema weight on model
             if self.use_ema:
-                weight = self.model.state_dict()
+                weight = copy.deepcopy(self.model.state_dict())
                 self.model.set_dict(self.ema.apply())
 
             self._compose_callback.on_epoch_end(self.status)
diff --git a/static/configs/ppyolo/ppyolov2_reader.yml b/static/configs/ppyolo/ppyolov2_reader.yml
index 02a385c1898f2f698b0adc852f42acf2712bab2b..d291ab1f7b02b4cca3dba589e552376e4d4d12f1 100644
--- a/static/configs/ppyolo/ppyolov2_reader.yml
+++ b/static/configs/ppyolo/ppyolov2_reader.yml
@@ -17,7 +17,6 @@ TrainReader:
       beta: 1.5
     - !ColorDistort {}
     - !RandomExpand
-      ratio: 2.0
       fill_value: [123.675, 116.28, 103.53]
     - !RandomCrop {}
     - !RandomFlipImage