diff --git a/mace/python/tools/converter_tool/transformer.py b/mace/python/tools/converter_tool/transformer.py
index c1fd9ee0323daf4be13565855ed8204cf3446ca0..6a07db0588ffd04bbd9480fd2a148c1fed423b93 100644
--- a/mace/python/tools/converter_tool/transformer.py
+++ b/mace/python/tools/converter_tool/transformer.py
@@ -1047,6 +1047,7 @@ class Transformer(base_converter.ConverterInterface):
         if self._option.device != DeviceType.CPU.value:
             return False
         net = self._model
+        transposed_weights = []
         for op in net.op:
             if op.type == MaceOp.MatMul.name:  # noqa
                 rhs = op.input[1]
@@ -1058,15 +1059,17 @@ class Transformer(base_converter.ConverterInterface):
                         arg.name = MaceKeyword.mace_transpose_b_str
                         arg.i = 0
                     if arg.i == 0:
-                        filter = self._consts[rhs]
-                        filter_data = np.array(filter.float_data).reshape(
-                            filter.dims)
-                        filter_data = filter_data.transpose(1, 0)
-                        filter.float_data[:] = filter_data.flat
-                        filter.dims[:] = filter_data.shape
                         arg.i = 1
-                        six.print_('Transpose matmul weight to shape:',
-                                   filter.dims)
+                        if rhs not in transposed_weights:
+                            filter = self._consts[rhs]
+                            filter_data = np.array(filter.float_data).reshape(
+                                filter.dims)
+                            filter_data = filter_data.transpose(1, 0)
+                            filter.float_data[:] = filter_data.flat
+                            filter.dims[:] = filter_data.shape
+                            transposed_weights.append(rhs)
+                            six.print_('Transpose matmul weight to shape:',
+                                       filter.dims)
 
     def transpose_filters(self):
         net = self._model