diff --git a/mindspore/_checkparam.py b/mindspore/_checkparam.py
index 7ec8631dfc..2412ab8e18 100644
--- a/mindspore/_checkparam.py
+++ b/mindspore/_checkparam.py
@@ -429,8 +429,9 @@ class Validator:
 
     @staticmethod
     def check_file_name_by_regular(target, reg=None, flag=re.ASCII, prim_name=None):
+        """Check whether file name is legitimate."""
         if reg is None:
-            reg = r"^[0-9a-zA-Z\_\-\.\/\\]*$"
+            reg = r"^[0-9a-zA-Z\_\-\.\/\\]+$"
         if re.match(reg, target, flag) is None:
             prim_name = f'in `{prim_name}`' if prim_name else ""
             raise ValueError("'{}' {} is illegal, it should be match regular'{}' by flags'{}'".format(
diff --git a/mindspore/ccsrc/transform/graph_ir/convert.cc b/mindspore/ccsrc/transform/graph_ir/convert.cc
index 47e8b23a9a..ad0c28ed03 100644
--- a/mindspore/ccsrc/transform/graph_ir/convert.cc
+++ b/mindspore/ccsrc/transform/graph_ir/convert.cc
@@ -596,8 +596,10 @@ void DfGraphConvertor::TraceOutput(const AnfNodePtr node) {
   // Trace value node
   if (node->isa<ValueNode>()) {
     auto op = Convert(anf_out);
-    graph_outputs_.emplace_back(std::make_pair(*op, ""));
-    AddGraphConstInput(op);
+    if (op != nullptr) {
+      graph_outputs_.emplace_back(std::make_pair(*op, ""));
+      AddGraphConstInput(op);
+    }
     return;
   }