diff --git a/tools/ci/check_copyright_ignore.txt b/tools/ci/check_copyright_ignore.txt
index 6370119c6f..58b789d697 100644
--- a/tools/ci/check_copyright_ignore.txt
+++ b/tools/ci/check_copyright_ignore.txt
@@ -3500,7 +3500,6 @@ tools/ci/python_packages/tiny_test_fw/TinyFW.py
 tools/ci/python_packages/tiny_test_fw/Utility/CIAssignTest.py
 tools/ci/python_packages/tiny_test_fw/Utility/CaseConfig.py
 tools/ci/python_packages/tiny_test_fw/Utility/GitlabCIJob.py
-tools/ci/python_packages/tiny_test_fw/Utility/SearchCases.py
 tools/ci/python_packages/tiny_test_fw/Utility/TestCase.py
 tools/ci/python_packages/tiny_test_fw/Utility/__init__.py
 tools/ci/python_packages/tiny_test_fw/bin/Runner.py
diff --git a/tools/ci/python_packages/tiny_test_fw/Utility/SearchCases.py b/tools/ci/python_packages/tiny_test_fw/Utility/SearchCases.py
index f61de3a7ec..8674bf57b8 100644
--- a/tools/ci/python_packages/tiny_test_fw/Utility/SearchCases.py
+++ b/tools/ci/python_packages/tiny_test_fw/Utility/SearchCases.py
@@ -1,30 +1,27 @@
-# Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http:#www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: Apache-2.0
 
 """ search test cases from a given file or path """
 import copy
 import fnmatch
 import os
+import sys
 import types
+from typing import List
 
 from . import load_source
 
 
-class Search(object):
+class Search:
+    """
+    This class is used as a class singleton. all the member functions are `classmethod`
+    """
     TEST_CASE_FILE_PATTERN = '*_test.py'
     SUPPORT_REPLICATE_CASES_KEY = ['target']
 
+    # this attribute would be modified while running
+    missing_import_warnings: List[str] = []
+
     @classmethod
     def _search_cases_from_file(cls, file_name):
         """ get test cases from test case .py file """
@@ -42,7 +39,8 @@ class Search(object):
                 except AttributeError:
                     continue
         except ImportError as e:
-            print('ImportError: \r\n\tFile:' + file_name + '\r\n\tError:' + str(e))
+            warning_str = 'ImortError: \r\n\tFile:' + file_name + '\r\n\tError:' + str(e)
+            cls.missing_import_warnings.append(warning_str)
 
         test_functions_out = []
         for case in test_functions:
@@ -132,8 +130,14 @@ class Search(object):
             test_case_paths = [test_case_paths]
         test_case_files = []
         for path in test_case_paths:
-            test_case_files.extend(cls._search_test_case_files(path, test_case_file_pattern or cls.TEST_CASE_FILE_PATTERN))
+            test_case_files.extend(
+                cls._search_test_case_files(path, test_case_file_pattern or cls.TEST_CASE_FILE_PATTERN))
         test_cases = []
         for test_case_file in test_case_files:
             test_cases += cls._search_cases_from_file(test_case_file)
+
+        if cls.missing_import_warnings:
+            print('\n\n'.join(cls.missing_import_warnings))
+            sys.exit(1)
+
         return test_cases