diff --git a/app/src/main/assets/print_demo.html b/app/src/main/assets/print_demo.html
index 24a48fd..39016e4 100644
--- a/app/src/main/assets/print_demo.html
+++ b/app/src/main/assets/print_demo.html
@@ -503,22 +503,23 @@
         showPttResult("[回调] " + msg);
     };
 
-    // ES6 特性测试函数
+    // ES6 特性测试函数（通过 eval 避免阻塞旧版 JS 引擎整体解析）
     function testES6Features() {
         try {
-            const arr = [1, 2, 3];
-            const [a, ...rest] = arr;
-            let sum = rest.reduce((acc, val) => acc + val, 0);
-            const myMap = new Map();
-            myMap.set('key', `Sum is ${sum}`);
-            
-            new Promise((resolve) => {
-                setTimeout(() => resolve(myMap.get('key')), 100);
-            }).then(res => {
-                alert(`ES6 引擎测试成功!\n解构: a=${a}\nPromise/Map 返回: ${res}`);
-            });
+            eval("\
+                const arr = [1, 2, 3];\
+                const [a, ...rest] = arr;\
+                let sum = rest.reduce((acc, val) => acc + val, 0);\
+                const myMap = new Map();\
+                myMap.set('key', `Sum is ${sum}`);\
+                new Promise((resolve) => {\
+                    setTimeout(() => resolve(myMap.get('key')), 100);\
+                }).then(res => {\
+                    alert(`ES6 引擎测试成功!\\n解构: a=${a}\\nPromise/Map 返回: ${res}`);\
+                });\
+            ");
         } catch(e) {
-            alert("ES6 测试失败: " + e.message);
+            alert("ES6 测试失败 (当前环境可能不支持): " + e.message);
         }
     }
     function addExitText() {
diff --git a/app/src/main/java/com/stand/standapp/utils/AppKiller.kt b/app/src/main/java/com/stand/standapp/utils/AppKiller.kt
index 305af7a..1098190 100644
--- a/app/src/main/java/com/stand/standapp/utils/AppKiller.kt
+++ b/app/src/main/java/com/stand/standapp/utils/AppKiller.kt
@@ -5,7 +5,12 @@ import timber.log.Timber
 
 object AppKiller {
 
+    private var isKilling = false
+
     fun killApp(context: Context, isCrash: Boolean = false) {
+        if (isKilling) return
+        isKilling = true
+        
         Timber.tag("AppKiller").i("Starting app cleanup. isCrash: $isCrash")
 
         try {
@@ -30,12 +35,6 @@ object AppKiller {
             Timber.tag("AppKiller").e(e, "Printer close failed")
         }
 
-        try {
-            LogManager.shutdown()
-        } catch (e: Exception) {
-            // ignore
-        }
-
         Timber.tag("AppKiller").i("Cleanup finished. Killing process.")
 
         if (!isCrash) {
@@ -44,6 +43,12 @@ object AppKiller {
             } catch (e: Exception) {}
         }
 
+        try {
+            // LogManager.shutdown() 会关闭其内部的线程池
+            // 调用后绝对不能再使用 Timber 打印日志，否则会抛出 RejectedExecutionException 导致死循环
+            LogManager.shutdown()
+        } catch (e: Exception) {}
+
         android.os.Process.killProcess(android.os.Process.myPid())
     }