diff --git a/mindspore/core/mindrt/src/thread/threadpool.cc b/mindspore/core/mindrt/src/thread/threadpool.cc
index a67502e32f653975ac570091008d583e6b39b984..1a9e675b92e17b5b1fd1d59e031f63eb28f69d4d 100644
--- a/mindspore/core/mindrt/src/thread/threadpool.cc
+++ b/mindspore/core/mindrt/src/thread/threadpool.cc
@@ -1,5 +1,5 @@
 /**
- * Copyright 2021 Huawei Technologies Co., Ltd
+ * Copyright 2021-2022 Huawei Technologies Co., Ltd
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -192,7 +192,7 @@ int ThreadPool::CreateThreads(size_t thread_num, const std::vector<int> &core_li
 
 int ThreadPool::ParallelLaunch(const Func &func, Content content, int task_num) const {
   // if single thread, run master thread
-  if (thread_num() <= 1 || task_num <= 1) {
+  if (task_num <= 1) {
     for (int i = 0; i < task_num; ++i) {
       int ret = func(content, i, 0, 1);
       if (ret != 0) {
diff --git a/mindspore/lite/src/lite_session.cc b/mindspore/lite/src/lite_session.cc
index cec037a72d425706253957e504f9c410fef85eff..2f94b9d387451a3a64ee560bc110712ac926b7f7 100644
--- a/mindspore/lite/src/lite_session.cc
+++ b/mindspore/lite/src/lite_session.cc
@@ -221,7 +221,7 @@ int LiteSession::ConvertTensorsData(const lite::LiteModel *model, size_t tensor_
   auto shape_info = dst_tensor->shape();
   if (shape_info.end() !=
       std::find_if(shape_info.begin(), shape_info.end(), [](const int shape) { return shape <= 0; })) {
-    MS_LOG(ERROR) << "Invalid shape size." << src_tensor->handler()->name()->c_str();
+    MS_LOG(ERROR) << "Invalid shape size, tensor name: " << src_tensor->handler()->name();
     return RET_ERROR;
   }
 
diff --git a/mindspore/lite/src/runtime/kernel/arm/string/skip_gram.cc b/mindspore/lite/src/runtime/kernel/arm/string/skip_gram.cc
index d161bbbe2383dc6316a946370c9f7d9b9119d1fc..d612975a999f6b09e42a8ec2a3fcdf2248465e31 100644
--- a/mindspore/lite/src/runtime/kernel/arm/string/skip_gram.cc
+++ b/mindspore/lite/src/runtime/kernel/arm/string/skip_gram.cc
@@ -1,5 +1,5 @@
 /**
- * Copyright 2020 Huawei Technologies Co., Ltd
+ * Copyright 2020-2022 Huawei Technologies Co., Ltd
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -32,6 +32,7 @@ int SkipGramCPUKernel::Prepare() {
   CHECK_LESS_RETURN(out_tensors_.size(), 1);
   CHECK_NULL_RETURN(in_tensors_[0]);
   CHECK_NULL_RETURN(out_tensors_[0]);
+  MS_CHECK_TRUE_RET(in_tensors_[0]->data_type() == kObjectTypeString, RET_ERROR);
   if (!InferShapeDone()) {
     return RET_OK;
   }
@@ -92,14 +93,15 @@ int SkipGramCPUKernel::Run() {
     } else {
       if (index > 0 && ((skip_gram_parameter_->include_all_ngrams && index <= skip_gram_parameter_->ngram_size) ||
                         (!skip_gram_parameter_->include_all_ngrams && index == skip_gram_parameter_->ngram_size))) {
-        std::vector<StringPack> gram(2 * index - 1);
+        const int twice = 2;
+        std::vector<StringPack> gram(twice * index - 1);
         char blank[1] = {' '};
         StringPack blank_str = {1, blank};
-        for (int i = 0; i < 2 * index - 2; i += 2) {
-          gram.at(i) = words.at(stack.at(i / 2));
+        for (int i = 0; i < twice * index - twice; i += twice) {
+          gram.at(i) = words.at(stack.at(i / twice));
           gram.at(i + 1) = blank_str;
         }
-        gram.at(2 * index - 2) = words.at(stack.at(index - 1));
+        gram.at(twice * index - twice) = words.at(stack.at(index - 1));
         result.push_back(gram);
       }
       index--;