diff --git a/x2paddle/op_mapper/onnx_op_mapper.py b/x2paddle/op_mapper/onnx_op_mapper.py
index a298cca58b955bb51c5016eae20a3c25647f9e41..ebc619c113a07e56661c142363ad9e5d7778fda4 100644
--- a/x2paddle/op_mapper/onnx_op_mapper.py
+++ b/x2paddle/op_mapper/onnx_op_mapper.py
@@ -646,7 +646,7 @@ class ONNXOpMapper(OpMapper):
         val_x = self.graph.get_node(node.layer.input[0], copy=True)
         val_y = self.graph.get_node(node.layer.output[0], copy=True)
         input_shape = val_x.out_shapes
-        output_shape = _val_y.out_shapes
+        output_shape = val_y.out_shapes
         assert input_shape is not None or output_shape is not None, 'poolnd not inferred'  # N
         if input_shape:
             poolnd = len(input_shape) - 2  # NC...