diff --git a/interfaces/innerkits/fs_manager/erofs_overlay/erofs_mount_overlay.c b/interfaces/innerkits/fs_manager/erofs_overlay/erofs_mount_overlay.c
index f74c27edb..65e372326 100644
--- a/interfaces/innerkits/fs_manager/erofs_overlay/erofs_mount_overlay.c
+++ b/interfaces/innerkits/fs_manager/erofs_overlay/erofs_mount_overlay.c
@@ -178,15 +178,6 @@ INIT_STATIC uint64_t GetBlockSize(const char *dev)
     return blockSize;
 }
 
-/* 字节对齐函数，基于alignment进行字节对齐 */
-INIT_STATIC uint64_t AlignTo(uint64_t base, uint64_t alignment)
-{
-    if (alignment == 0) {
-        return base;
-    }
-    return (((base - 1) / alignment + 1) * alignment);
-}
-
 INIT_STATIC int GetMapperAddr(const char *dev, uint64_t *start, uint64_t *length)
 {
     /* 获取EROFS文件系统大小 */
@@ -203,7 +194,7 @@ INIT_STATIC int GetMapperAddr(const char *dev, uint64_t *start, uint64_t *length
      */
     uint64_t imgSize = GetImgSize(dev, *start);
     if (imgSize > 0) {
-        *start = AlignTo(imgSize, ALIGN_BLOCK_SIZE);
+        *start += EXTHDR_BLKSIZE;
     }
 
     /* 获取分区大小，老分区布局：分区大小 = 镜像大小  新分区布局：分区大小 = 镜像大小 + 无镜像填充的分区空位 */