diff --git a/httprunner/api.py b/httprunner/api.py
index 0d3393a5..14de03ef 100644
--- a/httprunner/api.py
+++ b/httprunner/api.py
@@ -221,6 +221,7 @@ class HttpRunner(object):
 
             loaded_testcase = loader.loadTestsFromTestCase(TestSequense)
             setattr(loaded_testcase, "config", config)
+            setattr(loaded_testcase, "teststeps", testcase.get("teststeps", []))
             setattr(loaded_testcase, "runner", test_runner)
             loaded_testcases.append(loaded_testcase)
 
diff --git a/httprunner/context.py b/httprunner/context.py
index 35c42ceb..766aae22 100644
--- a/httprunner/context.py
+++ b/httprunner/context.py
@@ -110,8 +110,8 @@ class Context(object):
         """
         if level == "testcase":
             # testcase config request dict has been parsed in parse_tests
-            self.TESTCASE_SHARED_REQUEST_MAPPING = request_dict
-            return request_dict
+            self.TESTCASE_SHARED_REQUEST_MAPPING = copy.deepcopy(request_dict)
+            return self.TESTCASE_SHARED_REQUEST_MAPPING
 
         else:
             # teststep
diff --git a/httprunner/runner.py b/httprunner/runner.py
index 3eec4659..7394cb0b 100644
--- a/httprunner/runner.py
+++ b/httprunner/runner.py
@@ -164,8 +164,8 @@ class Runner(object):
         self._handle_skip_feature(teststep_dict)
 
         # prepare
-        extractors = teststep_dict.pop("extract", []) or teststep_dict.pop("extractors", [])
-        validators = teststep_dict.pop("validate", []) or teststep_dict.pop("validators", [])
+        extractors = teststep_dict.get("extract", []) or teststep_dict.get("extractors", [])
+        validators = teststep_dict.get("validate", []) or teststep_dict.get("validators", [])
         parsed_request = self.init_config(teststep_dict, level="teststep")
         self.context.update_teststep_variables_mapping("request", parsed_request)
 
diff --git a/tests/test_api.py b/tests/test_api.py
index 9baf5338..10831744 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -329,6 +329,10 @@ class TestHttpRunner(ApiServerUnittest):
             os.getcwd(), 'tests/data/demo_parameters.yml')
         runner = HttpRunner().run(testcase_file_path)
         summary = runner.summary
+        self.assertEqual(
+            summary["details"][0]["in_out"]["in"]["user_agent"],
+            "iOS/10.3"
+        )
         self.assertTrue(summary["success"])
         self.assertEqual(len(summary["details"]), 3 * 2)
         self.assertEqual(summary["stat"]["testsRun"], 3 * 2)