diff --git a/httprunner/parser.py b/httprunner/parser.py
index f4b82ff8..cd033299 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -503,7 +503,8 @@ def parse_string_variables(content, variables_mapping, functions_mapping):
             parsed_variable_value = parse_data(
                 variable_value,
                 variables_mapping,
-                functions_mapping
+                functions_mapping,
+                raise_if_variable_not_found=False
             )
 
         # TODO: replace variable label from $var to {{var}}
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 628343b8..153086fa 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -700,7 +700,7 @@ class TestParser(unittest.TestCase):
         self.assertEqual(test_dict["variables"]["num4"], "${sum_two($num0, 5)}")
         self.assertEqual(
             test_dict["request"]["url"],
-            "https://httprunner.org/api1/?num1=$num1&num2=$num2&num3=$num3&num4=$num4"
+            "https://httprunner.org/api1/?num1=3&num2=6&num3=10&num4=${sum_two($num0, 5)}"
         )
 
     def test_parse_tests_base_url_teststep_empty(self):