diff --git a/httprunner/parser.py b/httprunner/parser.py
index d7fb2f01..50074bb7 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -414,10 +414,14 @@ def parse_string_functions(content, variables_mapping, functions_mapping):
         kwargs = parse_data(kwargs, variables_mapping, functions_mapping)
 
         if func_name in ["parameterize", "P"]:
+            if len(args) != 1 or kwargs:
+                raise exceptions.ParamsError("P() should only pass in one argument!")
             from httprunner import loader
-            eval_value = loader.load_csv_file(*args)
+            eval_value = loader.load_csv_file(args[0])
         elif func_name in ["environ", "ENV"]:
-            eval_value = utils.get_os_environ(*args)
+            if len(args) != 1 or kwargs:
+                raise exceptions.ParamsError("ENV() should only pass in one argument!")
+            eval_value = utils.get_os_environ(args[0])
         else:
             func = get_mapping_function(func_name, functions_mapping)
             eval_value = func(*args, **kwargs)
diff --git a/tests/test_parser.py b/tests/test_parser.py
index b3a1ef17..84d9e948 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -451,3 +451,28 @@ class TestParser(unittest.TestCase):
         )
         self.assertIsInstance(parsed_testcases, list)
         self.assertEqual(parsed_testcases[0]["config"]["name"], '12311')
+
+    def test_parse_environ(self):
+        os.environ["PROJECT_KEY"] = "ABCDEFGH"
+        content = {
+            "variables": [
+                {"PROJECT_KEY": "${ENV(PROJECT_KEY)}"}
+            ]
+        }
+        result = parser.parse_data(content)
+
+        content = {
+            "variables": [
+                {"PROJECT_KEY": "${ENV(PROJECT_KEY, abc)}"}
+            ]
+        }
+        with self.assertRaises(exceptions.ParamsError):
+            parser.parse_data(content)
+
+        content = {
+            "variables": [
+                {"PROJECT_KEY": "${ENV(abc=123)}"}
+            ]
+        }
+        with self.assertRaises(exceptions.ParamsError):
+            parser.parse_data(content)