diff --git a/wenet/dataset/datapipes.py b/wenet/dataset/datapipes.py
index 46ca96d53..c50e538d3 100644
--- a/wenet/dataset/datapipes.py
+++ b/wenet/dataset/datapipes.py
@@ -452,6 +452,8 @@ def __init__(self,
             dp = IterableWrapperIterDataPipe(filenames)
             # 0 shard many jsonl files
             dp = dp.shuffle().repeat(cycle).shard(partition)
+            if shuffle:
+                self.dp = self.dp.shuffle(buffer_size=shuffle_size)
             # 1 read one json file
             self.dp = TextLineDataPipe(dp)
             self.dp = self.dp.prefetch(prefetch)