diff --git a/ascend_deployer/large_scale_deploy/tools/str_tool.py b/ascend_deployer/large_scale_deploy/tools/str_tool.py
index 35f73b5e86cd24a124a0e77f1dd1d1247b0be5aa..2023fcc3985a62949c1d022c7787f398366a4f02 100644
--- a/ascend_deployer/large_scale_deploy/tools/str_tool.py
+++ b/ascend_deployer/large_scale_deploy/tools/str_tool.py
@@ -3,8 +3,9 @@ import re
 
 
 class StrTool:
-
     _NON_WORD_PATTERN = re.compile(r"[^a-zA-Z0-9]")
+    _FURMULA_PATTERN = r'^[\w\s\.\+\-\*\/\(\)\'"]+$'
+    _EXCEPTION = ["()"]
     _SAFE_EVAL_SCOPE = {
         '__builtins__': None,
         'int': int,
@@ -12,9 +13,14 @@ class StrTool:
     }
 
     @classmethod
-    def to_py_field(cls, src_field: str):
+    def to_py_field(cls, src_field):
         return cls._NON_WORD_PATTERN.sub("_", src_field)
 
     @classmethod
-    def safe_eval(cls, expr: str):
-        return str(eval(expr, cls._SAFE_EVAL_SCOPE))
\ No newline at end of file
+    def safe_eval(cls, expr):
+        if not re.fullmatch(cls._FURMULA_PATTERN, expr):
+            raise ValueError("unsafe expression: {}".format(expr))
+        for k in cls._EXCEPTION:
+            if k in expr:
+                raise ValueError("unsafe expression: {}".format(expr))
+        return str(eval(expr, cls._SAFE_EVAL_SCOPE))
diff --git a/ascend_deployer/module_utils/inventory_file.py b/ascend_deployer/module_utils/inventory_file.py
index 92618f6bb72aa7580bafdd20b33dc91ae23ceadf..54f0083cd92874035ebac4e81a2bd33b086a6c05 100644
--- a/ascend_deployer/module_utils/inventory_file.py
+++ b/ascend_deployer/module_utils/inventory_file.py
@@ -33,6 +33,8 @@ class Mark:
 
 class StrTool:
     _NON_WORD_PATTERN = re.compile(r"[^a-zA-Z0-9]")
+    _FURMULA_PATTERN = r'^[\w\s\.\+\-\*\/\(\)\'"]+$'
+    _EXCEPTION = ["()"]
     _SAFE_EVAL_SCOPE = {
         '__builtins__': None,
         'int': int,
@@ -45,6 +47,11 @@ class StrTool:
 
     @classmethod
     def safe_eval(cls, expr):
+        if not re.fullmatch(cls._FURMULA_PATTERN, expr):
+            raise ValueError("unsafe expression: {}".format(expr))
+        for k in cls._EXCEPTION:
+            if k in expr:
+                raise ValueError("unsafe expression: {}".format(expr))
         return str(eval(expr, cls._SAFE_EVAL_SCOPE))
 
 
diff --git a/test/module_utils_test/test_inventory_file.py b/test/module_utils_test/test_inventory_file.py
index 073880fb8e001fed4c6ccdc4ae4001272a201272..171d583f8ee401a784d10959e33b0162be30ba8f 100644
--- a/test/module_utils_test/test_inventory_file.py
+++ b/test/module_utils_test/test_inventory_file.py
@@ -1,8 +1,10 @@
+import os
+import sys
 import unittest
-from ctypes import oledll
 from unittest.mock import patch
-
-from ascend_deployer.module_utils.inventory_file import Var, Host, HostParams, InventoryFile, ConfigrationError, IPRange
+from ascend_deployer.module_utils.inventory_file import (
+    Var, Host, HostParams, InventoryFile, ConfigrationError, IPRange, StrTool
+    )
 
 
 class TestVar(unittest.TestCase):
@@ -121,8 +123,8 @@ class TestHostParam(unittest.TestCase):
                 ['10.10.10.1 set_hostname="master-1"', '10.10.10.2 set_hostname="master-2"']
             ),
             (
-                'local_ip_port="{ip}:8080"',
-                ['10.10.10.1 local_ip_port="10.10.10.1:8080"', '10.10.10.2 local_ip_port="10.10.10.2:8080"']
+                'set_hostname="master-{str(index+1)+\'x\'}"',
+                ['10.10.10.1 set_hostname="master-2x"', '10.10.10.2 set_hostname="master-3x"']
             ),
             (
                 'local_ip_port="{ip}-{index}:8080"',
@@ -149,3 +151,31 @@ class TestInventoryFile(unittest.TestCase):
 
     def test_get_parsed_inventory_file_path(self):
         self.inventory_file.get_parsed_inventory_file_path()
+
+
+class TestStrTool(unittest.TestCase):
+
+    @patch("sys.exit")
+    def test_safe_eval(self, mock_exit):
+        test_cases = [
+            ("'master-'+str(1+20)+'x'", "master-21x"),
+            ("'master-'+'d'+'d'+str(1+1+1+1)", "master-dd4"),
+            ("'master.'+str(1+1)", "master.2")
+        ]
+        for param, expect in test_cases:
+            self.assertEqual(expect, StrTool.safe_eval(param))
+        
+        error_cases = [
+            "__import__('os')",
+            "'None'[0]",
+            "open('/etc')",
+            "'ddd'.upper()"
+            "'master-'+{open('/etc/passwd')}",
+        ]
+        for case in error_cases:
+            with self.assertRaises(Exception):
+                StrTool.safe_eval(case)
+
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file
diff --git a/test/test_utils.py b/test/test_utils.py
index 64815be61a239bf8ecc227abb9e689c48ae493cc..c610a309b7738896abf0739daee1a1e373b620d0 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -5,14 +5,13 @@ import unittest
 import errno
 from unittest.mock import patch
 
-sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
-
 from ascend_deployer.utils import Validator
 from ascend_deployer.utils import get_validated_env
 
 PATH_WHITE_LIST_LIN = string.digits + string.ascii_letters + '~-+_./ '
 MAX_PATH_LEN = 4096
 
+
 class TestGetValidatedEnv(unittest.TestCase):
 
     @patch('os.getenv')