diff --git a/fastNLP/core/utils.py b/fastNLP/core/utils.py
index d7092d48..27f266fa 100644
--- a/fastNLP/core/utils.py
+++ b/fastNLP/core/utils.py
@@ -223,8 +223,8 @@ def _move_model_to_device(model, device):
             model.cuda()
         return model
     else:
-        if not torch.cuda.is_available() and (
-                device != 'cpu' or (isinstance(device, torch.device) and device.type != 'cpu')):
+        if not torch.cuda.is_available() and ((isinstance(device, str) and device!='cpu') or
+         (isinstance(device, torch.device) and device.type != 'cpu')):
             raise ValueError("There is no usable gpu. set `device` as `cpu` or `None`.")
 
     if isinstance(model, torch.nn.DataParallel):