diff --git a/httprunner/loader.py b/httprunner/loader.py
index 24106311..700f7582 100644
--- a/httprunner/loader.py
+++ b/httprunner/loader.py
@@ -933,10 +933,9 @@ def load_project_tests(test_path, dot_env_path=None):
             "functions": {}
         }
 
-    # TODO: add tests layer temporally, remove later.
-    project_mapping["def-api"] = load_api_folder(os.path.join(project_working_directory, "tests", "api"))
+    project_mapping["def-api"] = load_api_folder(os.path.join(project_working_directory, "api"))
     # TODO: replace suite with testcases
-    project_mapping["def-testcase"] = load_test_folder(os.path.join(project_working_directory, "tests", "suite"))
+    project_mapping["def-testcase"] = load_test_folder(os.path.join(project_working_directory, "suite"))
 
     return project_mapping
 
diff --git a/httprunner/parser.py b/httprunner/parser.py
index 6c22c7e3..481ddc9d 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -629,24 +629,29 @@ def parse_tests(testcases, variables_mapping=None):
         for parameter_mapping in cartesian_product_parameters_list:
             testcase_dict = utils.deepcopy_dict(testcase)
             config = testcase_dict.get("config")
-
-            # parse config variables
+            # get config variables
             raw_config_variables = config.get("variables", [])
-            parsed_config_variables = parse_data(
-                raw_config_variables,
-                project_mapping["debugtalk"]["variables"],
-                project_mapping["debugtalk"]["functions"]
-            )
+            raw_config_variables_mapping = utils.ensure_mapping_format(raw_config_variables)
 
-            # priority: passed in > debugtalk.py > parameters > variables
-            # override variables mapping with parameters mapping
-            config_variables = utils.override_mapping_list(
-                parsed_config_variables, parameter_mapping)
-            # merge debugtalk.py module variables
+            # priority: passed in > .env > debugtalk.py > parameters > variables
+
+            config_variables = utils.deepcopy_dict(parameter_mapping)
             config_variables.update(project_mapping["debugtalk"]["variables"])
-            # override variables mapping with passed in variables_mapping
-            config_variables = utils.override_mapping_list(
-                config_variables, variables_mapping)
+            config_variables.update(variables_mapping)
+
+            for key, value in raw_config_variables_mapping.items():
+
+                if key in config_variables:
+                    # passed in & .env & parameters
+                    continue
+                else:
+                    # config variables
+                    parsed_value = parse_data(
+                        value,
+                        config_variables,
+                        project_mapping["debugtalk"]["functions"]
+                    )
+                    config_variables[key] = parsed_value
 
             testcase_dict["config"]["variables"] = config_variables
 
diff --git a/httprunner/utils.py b/httprunner/utils.py
index 8bf7700e..78e14c64 100644
--- a/httprunner/utils.py
+++ b/httprunner/utils.py
@@ -264,6 +264,39 @@ def update_ordered_dict(ordered_dict, override_mapping):
     return new_ordered_dict
 
 
+def ensure_mapping_format(variables):
+    """ ensure variables are in mapping format.
+
+    Args:
+        variables (list/dict/OrderedDict): original variables
+
+    Returns:
+        OrderedDict: ensured variables in OrderedDict
+
+    Examples:
+        >>> variables = [
+                {"a": 1},
+                {"b": 2}
+            ]
+        >>> print(ensure_mapping_format(variables))
+            OrderDict(
+                {
+                    "a": 1,
+                    "b": 2
+                }
+            )
+
+    """
+    if isinstance(variables, list):
+        variables_ordered_dict = convert_mappinglist_to_orderdict(variables)
+    elif isinstance(variables, (OrderedDict, dict)):
+        variables_ordered_dict = variables
+    else:
+        raise exceptions.ParamsError("variables format error!")
+
+    return variables_ordered_dict
+
+
 def override_mapping_list(variables, new_mapping):
     """ override variables with new mapping.
 
@@ -298,12 +331,7 @@ def override_mapping_list(variables, new_mapping):
             )
 
     """
-    if isinstance(variables, list):
-        variables_ordered_dict = convert_mappinglist_to_orderdict(variables)
-    elif isinstance(variables, (OrderedDict, dict)):
-        variables_ordered_dict = variables
-    else:
-        raise exceptions.ParamsError("variables error!")
+    variables_ordered_dict = ensure_mapping_format(variables)
 
     return update_ordered_dict(
         variables_ordered_dict,
diff --git a/tests/test_loader.py b/tests/test_loader.py
index 77a23a1a..104a855c 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -565,7 +565,7 @@ class TestSuiteLoader(unittest.TestCase):
         path = os.path.join(
             os.getcwd(), 'tests/data/demo_locust.yml')
         locust_tests = loader.load_locust_tests(path)
-        self.assertEqual(locust_tests["config"]["refs"]["env"]["UserName"], "debugtalk")
+        self.assertEqual(locust_tests["config"]["variables"]["UserName"], "debugtalk")
         self.assertEqual(len(locust_tests["tests"]), 10)
         self.assertEqual(locust_tests["tests"][0][0]["name"], "index")
         self.assertEqual(locust_tests["tests"][9][0]["name"], "user-agent")