diff --git a/animation-simulation/栈和队列/leetcode402移掉K位数字.md b/animation-simulation/栈和队列/leetcode402移掉K位数字.md
index 2ffe931..60e4b27 100644
--- a/animation-simulation/栈和队列/leetcode402移掉K位数字.md
+++ b/animation-simulation/栈和队列/leetcode402移掉K位数字.md
@@ -75,7 +75,7 @@ class Solution {
             }
             stack.push(i);
         }
-        while (k > 0) {
+        while (k > 0  && !stack.isEmpty()) {
             stack.pop();
             k--;
         }