diff --git a/x2paddle/op_mapper/paddle2onnx/opset9/opset.py b/x2paddle/op_mapper/paddle2onnx/opset9/opset.py
index 8cc238f63ac80b736a349316ad048a9a537b4503..14cba9a4f422cd042cb06e33a4f678291d74a564 100644
--- a/x2paddle/op_mapper/paddle2onnx/opset9/opset.py
+++ b/x2paddle/op_mapper/paddle2onnx/opset9/opset.py
@@ -398,6 +398,11 @@ class OpSet9(object):
             axis=op.attr('axis'))
         return node
 
+    def sum(self, op, block):
+        node = helper.make_node(
+            'Sum', inputs=op.input('X'), outputs=op.output('Out'))
+        return node
+
     def depthwise_conv2d(self, op, block):
         return self.conv2d(op, block)