diff --git a/httprunner/loader.py b/httprunner/loader.py
index afc79aa0..0f08f279 100644
--- a/httprunner/loader.py
+++ b/httprunner/loader.py
@@ -509,40 +509,23 @@ def load_api_folder(api_folder_path):
     return api_definition_mapping
 
 
-def load_debugtalk_py(start_path):
-    """ locate debugtalk.py file and returns PWD and debugtalk.py functions.
+def locate_debugtalk_py(start_path):
+    """ locate debugtalk.py file
 
     Args:
         start_path (str): start locating path, maybe testcase file path or directory path
 
     Returns:
-        tuple: (project_working_directory, debugtalk_functions)
+        str: debugtalk.py file path, None if not found
 
     """
     try:
         # locate debugtalk.py file.
         debugtalk_path = locate_file(start_path, "debugtalk.py")
-
-        # The folder contains debugtalk.py will be treated as PWD.
-        project_working_directory = os.path.dirname(debugtalk_path)
-
-        # add PWD to sys.path
-        sys.path.insert(0, project_working_directory)
-
-        # load debugtalk.py functions
-        debugtalk_functions = load_debugtalk_functions()
-
     except exceptions.FileNotFound:
+        debugtalk_path = None
 
-        # debugtalk.py not found, use os.getcwd() as PWD.
-        project_working_directory = os.getcwd()
-
-        # add PWD to sys.path
-        sys.path.insert(0, project_working_directory)
-
-        debugtalk_functions = {}
-
-    return project_working_directory, debugtalk_functions
+    return debugtalk_path
 
 
 def load_project_tests(test_path, dot_env_path=None):
@@ -557,15 +540,37 @@ def load_project_tests(test_path, dot_env_path=None):
         dict: project loaded api/testcases definitions, environments and debugtalk.py functions.
 
     """
-    # locate PWD and load debugtalk.py functions
-    project_working_directory, debugtalk_functions = load_debugtalk_py(test_path)
-    project_mapping["PWD"] = project_working_directory
-    project_mapping["functions"] = debugtalk_functions
+    # locate debugtalk.py file
+    debugtalk_path = locate_debugtalk_py(test_path)
 
-    # load .env
+    if debugtalk_path:
+        # The folder contains debugtalk.py will be treated as PWD.
+        project_working_directory = os.path.dirname(debugtalk_path)
+    else:
+        # debugtalk.py not found, use os.getcwd() as PWD.
+        project_working_directory = os.getcwd()
+
+    # add PWD to sys.path
+    sys.path.insert(0, project_working_directory)
+
+    # load .env file
+    # NOTICE:
+    # environment variable maybe loaded in debugtalk.py
+    # thus .env file should be loaded before loading debugtalk.py
     dot_env_path = dot_env_path or os.path.join(project_working_directory, ".env")
     project_mapping["env"] = load_dot_env_file(dot_env_path)
 
+    if debugtalk_path:
+        # load debugtalk.py functions
+        debugtalk_functions = load_debugtalk_functions()
+    else:
+        debugtalk_functions = {}
+
+    # locate PWD and load debugtalk.py functions
+
+    project_mapping["PWD"] = project_working_directory
+    project_mapping["functions"] = debugtalk_functions
+
     # load api
     tests_def_mapping["api"] = load_api_folder(os.path.join(project_working_directory, "api"))
 
diff --git a/tests/test_loader.py b/tests/test_loader.py
index 5630a14a..575802f3 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -208,21 +208,27 @@ class TestModuleLoader(unittest.TestCase):
         self.assertFalse(is_status_code_200(500))
 
     def test_load_debugtalk_py(self):
-        project_working_directory, debugtalk_functions = loader.load_debugtalk_py("tests/data/demo_testcase.yml")
+        loader.load_project_tests("tests/data/demo_testcase.yml")
+        project_working_directory = loader.project_mapping["PWD"]
+        debugtalk_functions = loader.project_mapping["functions"]
         self.assertEqual(
             project_working_directory,
             os.path.join(os.getcwd(), "tests")
         )
         self.assertIn("gen_md5", debugtalk_functions)
 
-        project_working_directory, debugtalk_functions = loader.load_debugtalk_py("tests/base.py")
+        loader.load_project_tests("tests/base.py")
+        project_working_directory = loader.project_mapping["PWD"]
+        debugtalk_functions = loader.project_mapping["functions"]
         self.assertEqual(
             project_working_directory,
             os.path.join(os.getcwd(), "tests")
         )
         self.assertIn("gen_md5", debugtalk_functions)
 
-        project_working_directory, debugtalk_functions = loader.load_debugtalk_py("httprunner/__init__.py")
+        loader.load_project_tests("httprunner/__init__.py")
+        project_working_directory = loader.project_mapping["PWD"]
+        debugtalk_functions = loader.project_mapping["functions"]
         self.assertEqual(
             project_working_directory,
             os.getcwd()