diff --git a/oneflow_onnx/oneflow2onnx/handlers/array.py b/oneflow_onnx/oneflow2onnx/handlers/array.py
index 199c0ea1cb5385f865807cb094916a4ae950d8ee..0185939f59bbbcbccda73b5c4b9ac0b7f6379eb0 100644
--- a/oneflow_onnx/oneflow2onnx/handlers/array.py
+++ b/oneflow_onnx/oneflow2onnx/handlers/array.py
@@ -121,12 +121,26 @@ class Flatten:
         assert dtype == 1, f"onnx opset version 1/9 only support float32 data_type!"
         assert start_dim >= 0, f"oneflow flatten can't support neagetive dim now!"
         node.attrs["axis"] = start_dim
+    
+    @classmethod
+    def Version_9(cls, ctx, node, **kwargs):
+        start_dim = node.attrs.get("start_dim", 1)
+        dtype = ctx.get_dtype(node.input_tensor_names[0])
+        assert dtype == 1, f"onnx opset version 1/9 only support float32 data_type!"
+        assert start_dim >= 0, f"oneflow flatten can't support neagetive dim now!"
+        node.attrs["axis"] = start_dim
 
     @classmethod
     def Version_11(cls, ctx, node, **kwargs):
         start_dim = node.attrs.get("start_dim", 1)
         assert start_dim >= 0, f"oneflow flatten can't support neagetive dim now!"
         node.attrs["axis"] = start_dim
+    
+    @classmethod
+    def Version_13(cls, ctx, node, **kwargs):
+        start_dim = node.attrs.get("start_dim", 1)
+        assert start_dim >= 0, f"oneflow flatten can't support neagetive dim now!"
+        node.attrs["axis"] = start_dim
 
 @flow_op("squeeze", "Squeeze")
 class Squeeze: