diff --git a/src/tim/transform/ops/stack_layout_inference.h b/src/tim/transform/ops/stack_layout_inference.h
index 7de26bd..f8e8fc4 100644
--- a/src/tim/transform/ops/stack_layout_inference.h
+++ b/src/tim/transform/ops/stack_layout_inference.h
@@ -41,9 +41,12 @@ class StackLayoutInfer : public OpLayoutInfer {
       : OpLayoutInfer(op, context) {}
   void OnInputs(
       std::vector<std::shared_ptr<vx::Tensor>>& next_tensors) override {
-    auto src_input = op_->impl()->InputsTensor()[0];
-    auto input_pv = context_->GetPermuteVector(src_input);
-
+    auto src_inputs = op_->impl()->InputsTensor();
+    std::shared_ptr<tim::vx::Tensor> normal_input;
+    int input_cnt=0;
+    for(; src_inputs[input_cnt]->IsConstTensor(); ++input_cnt);
+    normal_input = src_inputs[input_cnt];
+    auto input_pv = context_->GetPermuteVector(src_inputs[input_cnt]);
     int32_t axis = op_->impl()->node()->nn_param.stack.axis;
     auto stack = context_->infer_graph_->CreateOperation<vx::ops::Stack>(
         axis, op_->impl()->input_cnt_);
@@ -54,7 +57,7 @@ class StackLayoutInfer : public OpLayoutInfer {
     }
 
     if (axis < 0) {
-      axis += src_input->GetShape().size();
+      axis += normal_input->GetShape().size();
     }
 
     auto output_pv = MakeShared(input_pv->Rank() + 1);