diff --git a/keyBoard/VC/KBPermissionViewController.m b/keyBoard/VC/KBPermissionViewController.m
index ab41487..0f734e6 100644
--- a/keyBoard/VC/KBPermissionViewController.m
+++ b/keyBoard/VC/KBPermissionViewController.m
@@ -8,6 +8,8 @@
 #import "KBPermissionViewController.h"
 #import <AVFoundation/AVFoundation.h>
 
+static void *KBPermPlayerPresentationSizeContext = &KBPermPlayerPresentationSizeContext;
+
 @interface KBPermissionViewController ()
 @property (nonatomic, strong) UILabel *titleLabel;    // 标题
 @property (nonatomic, strong) UILabel *tipsLabel;     // 步骤提示
@@ -23,6 +25,9 @@
 @property (nonatomic, strong) AVPlayer *kb_permPlayer;
 @property (nonatomic, strong) AVPlayerLayer *kb_permPlayerLayer;
 
+// 承载视频的裁剪容器，高度固定为 KBFit(550)，内部内容从顶部开始显示，超出的部分从底部裁剪
+@property (nonatomic, strong) UIView *videoContainerView;
+
 @end
 
 @implementation KBPermissionViewController
@@ -36,7 +41,7 @@
     [self.view addSubview:self.closeButton];
     [self.view addSubview:self.titleLabel];
     [self.view addSubview:self.tipsLabel];
-//    [self.view addSubview:self.videoContainerView];
+    [self.view addSubview:self.videoContainerView];
     [self.view addSubview:self.openButton];
     [self.view addSubview:self.helpLabel];
 
@@ -70,13 +75,13 @@
         make.left.equalTo(self.titleLabel);
     }];
 
-    // 视频容器：左右距离 view 16，顶部距离 tipsLabel 30，底部距离按钮 36
-//    [self.videoContainerView mas_makeConstraints:^(MASConstraintMaker *make) {
-//        make.top.equalTo(self.tipsLabel.mas_bottom).offset(30);
-//        make.left.equalTo(self.view).offset(16);
-//        make.right.equalTo(self.view).offset(-16);
-//        make.bottom.equalTo(self.openButton.mas_top).offset(-36);
-//    }];
+    // 视频容器：左右各 25，顶部距离 tipsLabel 32，高度固定为 KBFit(550)
+    [self.videoContainerView mas_makeConstraints:^(MASConstraintMaker *make) {
+        make.top.equalTo(self.tipsLabel.mas_bottom).offset(32);
+        make.left.equalTo(self.view).offset(25);
+        make.right.equalTo(self.view).offset(-25);
+        make.height.mas_equalTo(KBFit(550));
+    }];
 
     [self.openButton mas_makeConstraints:^(MASConstraintMaker *make) {
         make.bottom.equalTo(self.view).offset(-KB_SAFE_BOTTOM-20);
@@ -107,13 +112,32 @@
 - (void)viewDidLayoutSubviews {
     [super viewDidLayoutSubviews];
     if (!self.kb_permPlayerLayer) { return; }
-    // 直接铺满整个视图区域，由 videoGravity 负责等比缩放
-    self.kb_permPlayerLayer.frame = CGRectMake(25, CGRectGetMaxY(self.tipsLabel.frame) + 32, KB_SCREEN_WIDTH - 50, 700);
+    // 以「宽度」为基准等比缩放视频，高度按宽高比计算，从 videoContainerView 顶部对齐，
+    // 多出的部分由容器（固定高度 KBFit(550)）从底部裁剪
+    CGSize videoSize = self.kb_permPlayer.currentItem.presentationSize;
+    if (videoSize.width <= 0) { return; } // 尚未拿到真实尺寸时先不布局
+
+    CGFloat aspect = videoSize.height / videoSize.width;
+    CGRect containerBounds = self.videoContainerView.bounds;
+    if (CGRectIsEmpty(containerBounds)) { return; }
+
+    CGFloat width  = CGRectGetWidth(containerBounds); // 以容器宽度为基准
+    CGFloat height = width * aspect;                  // 按宽度等比算出真实视频高度
+
+    // 顶部对齐，y = 0；若 height > 容器高度，则底部会被裁剪
+    self.kb_permPlayerLayer.frame = CGRectMake(0, 0, width, height);
 }
 
 - (void)dealloc {
     // 移除通知监听
     [[NSNotificationCenter defaultCenter] removeObserver:self];
+    @try {
+        [self.kb_permPlayer.currentItem removeObserver:self
+                                           forKeyPath:@"presentationSize"
+                                              context:KBPermPlayerPresentationSizeContext];
+    } @catch (__unused NSException *e) {
+        // ignore if observer not set
+    }
 }
 
 #pragma mark - Actions
@@ -180,13 +204,18 @@
 
     self.kb_permPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.kb_permPlayer];
     // 使用等比模式，按我们计算好的 frame 显示；多余部分由容器裁剪
-    self.kb_permPlayerLayer.videoGravity = AVLayerVideoGravityResize;
+    self.kb_permPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
     self.kb_permPlayerLayer.cornerRadius = 20;
     self.kb_permPlayerLayer.masksToBounds = true;
 
-    // 将视频图层插在按钮下面，保证按钮显示在视频之上
-    CALayer *buttonLayer = self.openButton.layer;
-    [self.view.layer insertSublayer:self.kb_permPlayerLayer below:buttonLayer];
+    // 将视频图层添加到裁剪容器内部，由容器控制圆角与裁剪
+    [self.videoContainerView.layer addSublayer:self.kb_permPlayerLayer];
+
+    // 监听 presentationSize 变化，尺寸从 {0,0} 变为真实值时触发布局
+    [item addObserver:self
+           forKeyPath:@"presentationSize"
+              options:NSKeyValueObservingOptionNew
+              context:KBPermPlayerPresentationSizeContext];
 
     // 播放结束后从头循环
     [[NSNotificationCenter defaultCenter] addObserver:self
@@ -208,6 +237,20 @@
     }];
 }
 
+- (void)observeValueForKeyPath:(NSString *)keyPath
+                      ofObject:(id)object
+                        change:(NSDictionary<NSKeyValueChangeKey,id> *)change
+                       context:(void *)context {
+    if (context == KBPermPlayerPresentationSizeContext) {
+        // presentationSize 从 {0,0} 变为真实尺寸时，触发布局更新
+        dispatch_async(dispatch_get_main_queue(), ^{
+            [self.view setNeedsLayout];
+        });
+        return;
+    }
+    [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
+}
+
 #pragma mark - Lazy Subviews
 
 - (UIButton *)backButton {
@@ -243,7 +286,6 @@
     return _tipsLabel;
 }
 
-
 - (UIButton *)openButton {
     if (!_openButton) {
         _openButton = [UIButton buttonWithType:UIButtonTypeCustom];
@@ -286,6 +328,7 @@
     }
     return _bgImageView;
 }
+
 - (UIImageView *)redImageView{
     if (!_redImageView) {
         _redImageView = [[UIImageView alloc] init];
@@ -294,4 +337,14 @@
     return _redImageView;
 }
 
+- (UIView *)videoContainerView {
+    if (!_videoContainerView) {
+        _videoContainerView = [UIView new];
+        _videoContainerView.backgroundColor = [UIColor clearColor];
+        _videoContainerView.layer.cornerRadius = 20.0;
+        _videoContainerView.clipsToBounds = YES; // 超出容器高度的部分直接裁剪
+    }
+    return _videoContainerView;
+}
+
 @end