diff --git a/src/Validator.php b/src/Validator.php
index 4e71aeb..effafb5 100644
--- a/src/Validator.php
+++ b/src/Validator.php
@@ -14,6 +14,7 @@ use Hyperf\Di\Annotation\Inject;
 use Hyperf\Validation\Contract\ValidatorFactoryInterface;
 use Hyperf\Validation\Validator as HyperfValidator;
 use RuntimeException;
+use Hyperf\Collection\Arr;
 
 abstract class Validator
 {
@@ -128,6 +129,17 @@ abstract class Validator
         }
     }
 
+    /**
+     * 获取待验证数据中指定键的值.
+     * 如果不存在该键，则返回null.
+     * @param string $key 待获取的键名
+     * @return mixed 键对应的值
+     */
+    protected function getDataByKey(string $key): mixed
+    {
+        return Arr::get($this->data, $key);
+    }
+
     /**
      * 定义场景验证规则（子类实现）.
      */