diff --git a/httprunner/utils.py b/httprunner/utils.py
index 285afdd7..bed9af5c 100644
--- a/httprunner/utils.py
+++ b/httprunner/utils.py
@@ -264,14 +264,22 @@ def lower_dict_keys(origin_dict):
     }
 
 def lower_config_dict_key(config_dict):
-    """ convert key in config dict to lower case, convertion will occur in two places:
+    """ convert key in config dict to lower case, convertion will occur in three places:
         1, all keys in config dict;
         2, all keys in config["request"]
+        3, all keys in config["request"]["headers"]
     """
+    # convert keys in config dict
     config_dict = lower_dict_keys(config_dict)
+
     if "request" in config_dict:
+        # convert keys in config["request"]
         config_dict["request"] = lower_dict_keys(config_dict["request"])
 
+        # convert keys in config["request"]["headers"]
+        if "headers" in config_dict["request"]:
+            config_dict["request"]["headers"] = lower_dict_keys(config_dict["request"]["headers"])
+
     return config_dict
 
 def convert_to_order_dict(map_list):
diff --git a/tests/test_context.py b/tests/test_context.py
index 742076b0..3d14ea2c 100644
--- a/tests/test_context.py
+++ b/tests/test_context.py
@@ -207,7 +207,7 @@ class VariableBindsUnittest(ApiServerUnittest):
         self.assertEqual(len(parsed_request["headers"]["random"]), 5)
         self.assertIn("data", parsed_request)
         self.assertEqual(parsed_request["data"], testcase["variables"][2]["data"])
-        self.assertEqual(parsed_request["headers"]["SECRET_KEY"], "DebugTalk")
+        self.assertEqual(parsed_request["headers"]["secret_key"], "DebugTalk")
 
     def test_exec_content_functions(self):
         test_runner = runner.Runner()
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 6c8c1b09..84a8b0c1 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -259,8 +259,8 @@ class TestUtils(ApiServerUnittest):
         self.assertIn("request", new_dict)
         self.assertIn("method", new_dict["request"])
         self.assertIn("headers", new_dict["request"])
-        self.assertIn("Accept", new_dict["request"]["headers"])
-        self.assertIn("User-Agent", new_dict["request"]["headers"])
+        self.assertIn("accept", new_dict["request"]["headers"])
+        self.assertIn("user-agent", new_dict["request"]["headers"])
 
         origin_dict = {
             "Name": "test",