diff --git a/ding/torch_utils/data_helper.py b/ding/torch_utils/data_helper.py
index 95953f8d9d..e34df5308a 100644
--- a/ding/torch_utils/data_helper.py
+++ b/ding/torch_utils/data_helper.py
@@ -218,7 +218,10 @@ def transform(d):
     elif isinstance(item, bool) or isinstance(item, str):
         return item
     elif np.isscalar(item):
-        return np.array(item)
+        if dtype is None:
+            return np.array(item)
+        else:
+            return np.array(item, dtype=dtype)
     elif item is None:
         return None
     else: