diff --git a/Dynamic programming/Fibonacci_Recursion.ts b/Dynamic programming/Fibonacci_Recursion.ts
index cac027e..6fefb42 100644
--- a/Dynamic programming/Fibonacci_Recursion.ts	
+++ b/Dynamic programming/Fibonacci_Recursion.ts	
@@ -1,7 +1,11 @@
+let ve = 0;
 const Fibonacci_Recursion = (n: number): number => {
   if (n <= 0) return 0;
   if (n === 1) return n;
 
+  ++ve;
+  if (ve >= 2000) throw new Error(`层级过深: ${ve}`);
+
   return Fibonacci_Recursion(n - 1) + Fibonacci_Recursion(n - 2);
 };