diff --git a/federatedscope/attack/auxiliary/poisoning_data.py b/federatedscope/attack/auxiliary/poisoning_data.py
index 8a0c4fcdf..23d7e79dd 100644
--- a/federatedscope/attack/auxiliary/poisoning_data.py
+++ b/federatedscope/attack/auxiliary/poisoning_data.py
@@ -245,6 +245,10 @@ def add_trans_normalize(data, ctx):
     '''
 
     for key in data:
+        ori_dataset = data[key].dataset
+        list_dataset = [item for item in ori_dataset]
+        data[key] = DataLoader(list_dataset, batch_size=ctx.data.batch_size, shuffle=ctx.data.shuffle, num_workers=ctx.data.num_workers)
+        
         num_dataset = len(data[key].dataset)
         mean, std = ctx.attack.mean, ctx.attack.std
         if "CIFAR10" in ctx.data.type and key == MODE.TRAIN: