diff --git a/parser/tensorflow/graph_optimizer.cc b/parser/tensorflow/graph_optimizer.cc
index ce56a6b..500420c 100644
--- a/parser/tensorflow/graph_optimizer.cc
+++ b/parser/tensorflow/graph_optimizer.cc
@@ -93,6 +93,7 @@ Status ParserGraphOptimizer::GetFusionCluster(const bool has_get_next, const boo
   GE_CHECK_NOTNULL(graph_);
   for (auto node : graph_->GetDirectNode()) {
     GE_CHECK_NOTNULL(node);
+    GE_CHECK_NOTNULL(node->GetOpDesc());
     GE_IF_BOOL_EXEC(node->GetOpDesc()->GetType() != ge::parser::FRAMEWORK_OP_TYPE, continue)
     string type;
     GE_CHK_STATUS_RET(ge::parser::GetOriginalType(node, type));
@@ -289,6 +290,7 @@ Status ParserGraphOptimizer::InsertNode(ge::ComputeGraphPtr sub_graph, vector<ge
     GE_CHECK_NOTNULL(node);
     OpDescPtr op_def = node->GetOpDesc();
     NodePtr new_node = sub_graph->AddNode(op_def);
+    GE_CHECK_NOTNULL(new_node);
     node_map[node->GetName()] = new_node;
 
     // Input
@@ -445,6 +447,7 @@ Status ParserGraphOptimizer::RebuildFusionNode(vector<ge::InDataAnchorPtr> &inpu
                                                vector<ge::InControlAnchorPtr> &input_control_anchors,
                                                vector<ge::OutControlAnchorPtr> &output_control_anchors,
                                                ge::NodePtr fusion_node) {
+  GE_CHECK_NOTNULL(fusion_node);
   int32_t src_index = 0;
 
   for (auto out_anchor : output_anchors) {
diff --git a/parser/tensorflow/tensorflow_data_parser.cc b/parser/tensorflow/tensorflow_data_parser.cc
index abe8a11..6042160 100644
--- a/parser/tensorflow/tensorflow_data_parser.cc
+++ b/parser/tensorflow/tensorflow_data_parser.cc
@@ -110,7 +110,7 @@ Status TensorFlowDataParser::ParseInputFromUser(const Message *op_src, const ge:
   std::string name = op_def->GetName();
   if (input_dims.count(name) == 0) {
     GELOGI("input shape of node %s is not designated ,need parse from model", name.c_str());
-    for (uint32_t i = 0; i < model_input_dims_v.size(); i++) {
+    for (size_t i = 0; i < model_input_dims_v.size(); ++i) {
       user_input_dims_v.push_back(model_input_dims_v[i]);
     }
 
@@ -138,7 +138,7 @@ Status TensorFlowDataParser::ParseInputFromUser(const Message *op_src, const ge:
 }
 
 Status TensorFlowDataParser::CheckInputShape(const std::string &name) {
-  for (uint32_t i = 0; i < user_input_dims_v.size(); i++) {
+  for (size_t i = 0; i < user_input_dims_v.size(); ++i) {
     // if input_shape has some placeholders, user should designate them.
     // dim i = 0, means empty tensor.
     // dim i = -1 or -2, means unknown shape.