首先要判斷有沒有存進相冊的權限，如果有就可以直接存，如果沒有提醒用戶開啟訪問相冊的權限。
直接開代碼：

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self saveMyFavoriteImageToCustomAlbum];
}

//開始存儲我的圖片到自定義的相冊
- (void)saveMyFavoriteImageToCustomAlbum
{
    //判斷有沒有訪問相冊的權限
    PHAuthorizationStatus oldStatus = [PHPhotoLibrary authorizationStatus];
    if (oldStatus != PHAuthorizationStatusAuthorized)
    {
        //申請訪問相冊的權限
        [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
            dispatch_async(dispatch_get_main_queue(), ^{
                if (status != PHAuthorizationStatusAuthorized)
                {
                    NSLog(@"沒有權限");
                }
                else
                {
                    NSLog(@"有權限");
                    UIImage *image = [UIImage imageNamed:@"傳入想要存儲的圖片"];
                    [self savedPhotoToAlbumWithImage:image album:@"相冊的名字"];
                }
            });
        }];
    }
    else
    {
        NSLog(@"有權限");
        UIImage *image = [UIImage imageNamed:@"傳入想要存儲的圖片"];
        [self savedPhotoToAlbumWithImage:image album:@"相冊的名字"];
    }
}

#pragma mark - 適配iOS8以上存儲圖片
//把圖片存入指定的相冊
- (void)savedPhotoToAlbumWithImage:(UIImage *)image album:(NSString *)photoAlbum
{
    //判斷圖片是不是為空
    if (image == nil || [PHPhotoLibrary authorizationStatus] != PHAuthorizationStatusAuthorized)
    {
        return;
    }
    //存儲圖片
    PHFetchResult<PHAsset *> *createdAssets = [self loadPhotoAssetsWithImage:image];
    if (createdAssets == nil)
    {
        //保存圖片失敗！
        return;
    }
    //創建相冊
    PHAssetCollection *createdCollection = [self loadAlbumWithName:photoAlbum];
    if (createdCollection == nil)
    {
        //創建或者獲取相冊失敗！
        return;
    }
    
    NSError *error = nil;
    //執行存儲圖片和創建相冊
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:createdCollection];
        [request insertAssets:createdAssets atIndexes:[NSIndexSet indexSetWithIndex:0]];
    } error:&error];
}

//創建一個相冊
- (PHAssetCollection *)loadAlbumWithName:(NSString *)albumName
{
    NSString *albumNameTitle = (albumName.length != 0)? albumName : @"";
    //抓取所有的自定義相冊（保證相冊只被創建一個）
    PHFetchResult<PHAssetCollection *> *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    PHAssetCollection *createdCollection = nil;
    for (PHAssetCollection *collection in collections)
    {
        if ([collection.localizedTitle isEqualToString:albumNameTitle])
        {
            createdCollection = collection;
            break;
        }
    }
    //當前APP對應的自定義相冊沒有被創建過
    NSError *error = nil;
    if (createdCollection == nil)
    {
        __block NSString *createdCollectionID;
        [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
            //創建一個相冊,拿到相冊的唯一標識符
            createdCollectionID = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:albumNameTitle].placeholderForCreatedAssetCollection.localIdentifier;
        } error:&error];
        
        //根據相冊的唯一標識符拿到相冊
        createdCollection = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createdCollectionID] options:nil].firstObject;
    }
    return createdCollection;
}

//保存圖片
- (PHFetchResult<PHAsset *> *)loadPhotoAssetsWithImage:(UIImage *)saveImage
{
    NSError *error = nil;
    __block NSString *assetID = nil;
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{//同步
        assetID = [PHAssetChangeRequest creationRequestForAssetFromImage:saveImage].placeholderForCreatedAsset.localIdentifier;
    } error:&error];
    if (error)
    {
        return nil;
    }
    return [PHAsset fetchAssetsWithLocalIdentifiers:@[assetID] options:nil];
}