diff --git a/httprunner/step_request.py b/httprunner/step_request.py
index f872470e..81f1015b 100644
--- a/httprunner/step_request.py
+++ b/httprunner/step_request.py
@@ -1,3 +1,4 @@
+import copy
 import time
 from typing import Any, Dict, List, Text, Union
 
@@ -67,13 +68,11 @@ def call_hooks(
 
 def run_step_request(runner: HttpRunner, step: TStep) -> StepResult:
     """run teststep: request"""
-    step_start_variables = step.variables
-
     step_result = StepResult(
         name=step.name,
         success=False,
     )
-    step.variables = runner.merge_step_variables(step.variables)
+    step_variables = runner.merge_step_variables(step.variables)
     start_time = time.time()
 
 
@@ -82,16 +81,16 @@ def run_step_request(runner: HttpRunner, step: TStep) -> StepResult:
     prepare_upload_step(step, functions)
     request_dict = step.request.dict()
     request_dict.pop("upload", None)
-    parsed_request_dict = runner.parser.parse_data(request_dict, step.variables)
+    parsed_request_dict = runner.parser.parse_data(request_dict, step_variables)
     parsed_request_dict["headers"].setdefault(
         "HRUN-Request-ID",
         f"HRUN-{runner.case_id}-{str(int(time.time() * 1000))[-6:]}",
     )
-    step.variables["request"] = parsed_request_dict
+    step_variables["request"] = parsed_request_dict
 
     # setup hooks
     if step.setup_hooks:
-        call_hooks(runner, step.setup_hooks, step.variables, "setup request")
+        call_hooks(runner, step.setup_hooks, step_variables, "setup request")
 
     # prepare arguments
     config = runner.get_config()
@@ -104,11 +103,11 @@ def run_step_request(runner: HttpRunner, step: TStep) -> StepResult:
     # request
     resp = runner.session.request(method, url, **parsed_request_dict)
     resp_obj = ResponseObject(resp, runner.parser)
-    step.variables["response"] = resp_obj
+    step_variables["response"] = resp_obj
 
     # teardown hooks
     if step.teardown_hooks:
-        call_hooks(runner, step.teardown_hooks, step.variables, "teardown request")
+        call_hooks(runner, step.teardown_hooks, step_variables, "teardown request")
 
     def log_req_resp_details():
         err_msg = "\n{} DETAILED REQUEST & RESPONSE {}\n".format("*" * 32, "*" * 32)
@@ -134,12 +133,11 @@ def run_step_request(runner: HttpRunner, step: TStep) -> StepResult:
 
     # extract
     extractors = step.extract
-    extract_mapping = resp_obj.extract(extractors, step.variables)
+    extract_mapping = resp_obj.extract(extractors, step_variables)
     step_result.export_vars = extract_mapping
 
-    variables_mapping = step.variables
+    variables_mapping = step_variables
     variables_mapping.update(extract_mapping)
-    step_start_variables.update(extract_mapping)
 
     # validate
     validators = step.validators
@@ -153,8 +151,6 @@ def run_step_request(runner: HttpRunner, step: TStep) -> StepResult:
         session_data = runner.session.data
         session_data.success = step_result.success
         session_data.validators = resp_obj.validation_results
-        step.variables.clear()
-        step.variables = step_start_variables
 
         # save step data
         step_result.data = session_data
diff --git a/httprunner/step_sql_request.py b/httprunner/step_sql_request.py
index d26d6fa6..b87d714d 100644
--- a/httprunner/step_sql_request.py
+++ b/httprunner/step_sql_request.py
@@ -44,17 +44,16 @@ def ensure_sql_ready():
 
 def run_step_sql_request(runner: HttpRunner, step: TStep) -> StepResult:
     """run teststep:sql request"""
-    step_start_variables = step.variables
     start_time = time.time()
 
     step_result = StepResult(
         name=step.name,
         success=False,
     )
-    step.variables = runner.merge_step_variables(step.variables)
+    step_variables = runner.merge_step_variables(step.variables)
     # parse
     request_dict = step.sql_request.dict()
-    parsed_request_dict = runner.parser.parse_data(request_dict, step.variables)
+    parsed_request_dict = runner.parser.parse_data(request_dict, step_variables)
     config = runner.get_config()
     parsed_request_dict["db_config"]["psm"] = (
         parsed_request_dict["db_config"]["psm"] or config.db.psm
@@ -93,7 +92,7 @@ def run_step_sql_request(runner: HttpRunner, step: TStep) -> StepResult:
 
     # setup hooks
     if step.setup_hooks:
-        call_hooks(runner, step.setup_hooks, step.variables, "setup request")
+        call_hooks(runner, step.setup_hooks, step_variables, "setup request")
 
     logger.info(f"Executing SQL: {parsed_request_dict['sql']}")
     if step.sql_request.method == SqlMethodEnum.FETCHONE:
@@ -115,11 +114,11 @@ def run_step_sql_request(runner: HttpRunner, step: TStep) -> StepResult:
             f"step.sql_request.method {parsed_request_dict['method']} not support"
         )
     resp_obj = SqlResponseObject(sql_resp, parser=runner.parser)
-    step.variables["sql_response"] = resp_obj
+    step_variables["sql_response"] = resp_obj
 
     # teardown hooks
     if step.teardown_hooks:
-        call_hooks(runner, step.teardown_hooks, step.variables, "teardown request")
+        call_hooks(runner, step.teardown_hooks, step_variables, "teardown request")
 
     def log_sql_req_resp_details():
         err_msg = "\n{} SQL DETAILED REQUEST & RESPONSE {}\n".format("*" * 32, "*" * 32)
@@ -145,7 +144,7 @@ def run_step_sql_request(runner: HttpRunner, step: TStep) -> StepResult:
     extract_mapping = resp_obj.extract(extractors)
     step_result.export_vars = extract_mapping
 
-    variables_mapping = step.variables
+    variables_mapping = step_variables
     variables_mapping.update(extract_mapping)
 
     # validate
@@ -160,8 +159,6 @@ def run_step_sql_request(runner: HttpRunner, step: TStep) -> StepResult:
         session_data = runner.session.data
         session_data.success = step_result.success
         session_data.validators = resp_obj.validation_results
-        step.variables.clear()
-        step.variables = step_start_variables
 
         # save step data
         step_result.data = session_data
diff --git a/httprunner/step_thrift_request.py b/httprunner/step_thrift_request.py
index 9425dfab..8e6ed253 100644
--- a/httprunner/step_thrift_request.py
+++ b/httprunner/step_thrift_request.py
@@ -52,17 +52,16 @@ def ensure_thrift_ready():
 
 def run_step_thrift_request(runner: HttpRunner, step: TStep) -> StepResult:
     """run teststep:thrift request"""
-    step_start_variables = step.variables
     start_time = time.time()
 
     step_result = StepResult(
         name=step.name,
         success=False,
     )
-    step.variables = runner.merge_step_variables(step.variables)
+    step_variables = runner.merge_step_variables(step.variables)
     # parse
     request_dict = step.thrift_request.dict()
-    parsed_request_dict = runner.parser.parse_data(request_dict, step.variables)
+    parsed_request_dict = runner.parser.parse_data(request_dict, step_variables)
     config = runner.get_config()
     parsed_request_dict["psm"] = parsed_request_dict["psm"] or config.thrift.psm
     parsed_request_dict["env"] = parsed_request_dict["env"] or config.thrift.env
@@ -98,7 +97,7 @@ def run_step_thrift_request(runner: HttpRunner, step: TStep) -> StepResult:
     #     "HRUN-Request-ID",
     #     f"HRUN-{self.__case_id}-{str(int(time.time() * 1000))[-6:]}",
     # )
-    step.variables["thrift_request"] = parsed_request_dict
+    step_variables["thrift_request"] = parsed_request_dict
 
     psm = parsed_request_dict["psm"]
     if not runner.thrift_client:
@@ -120,18 +119,18 @@ def run_step_thrift_request(runner: HttpRunner, step: TStep) -> StepResult:
 
     # setup hooks
     if step.setup_hooks:
-        call_hooks(runner, step.setup_hooks, step.variables, "setup request")
+        call_hooks(runner, step.setup_hooks, step_variables, "setup request")
 
     # thrift request
     resp = runner.thrift_client.send_request(
         parsed_request_dict["params"], parsed_request_dict["method"]
     )
     resp_obj = ThriftResponseObject(resp, parser=runner.parser)
-    step.variables["thrift_response"] = resp_obj
+    step_variables["thrift_response"] = resp_obj
 
     # teardown hooks
     if step.teardown_hooks:
-        call_hooks(runner, step.teardown_hooks, step.variables, "teardown request")
+        call_hooks(runner, step.teardown_hooks, step_variables, "teardown request")
 
     def log_thrift_req_resp_details():
         err_msg = "\n{} THRIFT DETAILED REQUEST & RESPONSE {}\n".format(
@@ -159,7 +158,7 @@ def run_step_thrift_request(runner: HttpRunner, step: TStep) -> StepResult:
     extract_mapping = resp_obj.extract(extractors)
     step_result.export_vars = extract_mapping
 
-    variables_mapping = step.variables
+    variables_mapping = step_variables
     variables_mapping.update(extract_mapping)
 
     # validate
@@ -174,8 +173,6 @@ def run_step_thrift_request(runner: HttpRunner, step: TStep) -> StepResult:
         session_data = runner.session.data
         session_data.success = step_result.success
         session_data.validators = resp_obj.validation_results
-        step.variables.clear()
-        step.variables = step_start_variables
 
         # save step data
         step_result.data = session_data