diff --git a/packages/update/src/UpdateSDK.ts b/packages/update/src/UpdateSDK.ts
index 5c1c2a1..950eb98 100644
--- a/packages/update/src/UpdateSDK.ts
+++ b/packages/update/src/UpdateSDK.ts
@@ -2,6 +2,7 @@ import AsyncStorage from '@react-native-async-storage/async-storage'
 import { Linking, Platform } from 'react-native'
 import { apiRequest, getConfig, getUserId, _registerUserInfoHandler } from '@xuqm/rn-common'
 import { getAppVersionCode, getAppVersionName, _devSetAppVersion } from './NativeVersion'
+import { md5 } from './md5'
 
 // ─── Types (public) ────────────────────────────────────────────────────────────
 
@@ -343,6 +344,9 @@ export const UpdateSDK = {
 
   /**
    * Android APK 直接下载并调起系统安装器。
+   *
+   * 当前实现使用 Linking.openURL 打开下载链接，由浏览器完成下载和安装引导。
+   * 如需应用内下载 + 静默安装，宿主可集成 react-native-blob-util 并自行实现。
    */
   async downloadAndInstallApk(
     downloadUrl: string,
@@ -352,15 +356,7 @@ export const UpdateSDK = {
     },
   ): Promise<void> {
     if (Platform.OS !== 'android') throw new Error('[UpdateSDK] APK install is Android-only.')
-    // NativeApkInstall 由宿主提供（TurboModule），若未注入则 fallback 到 Linking
-    try {
-      // eslint-disable-next-line @typescript-eslint/no-require-imports
-      const { XuqmApkInstall } = require('./NativeApkInstall') as { XuqmApkInstall: { installApk(url: string, sha256?: string | null): Promise<void> } }
-      await XuqmApkInstall.installApk(downloadUrl, options?.sha256 ?? null)
-    } catch {
-      // Native module not available — fallback to Linking
-      await Linking.openURL(downloadUrl)
-    }
+    await Linking.openURL(downloadUrl)
   },
 
   // ── 插件（Bundle）热更新 ──────────────────────────────────────────────────
@@ -429,6 +425,16 @@ export const UpdateSDK = {
 
     const source = await _downloadText(info.downloadUrl, options?.onProgress)
 
+    // MD5 校验
+    if (info.md5) {
+      const actual = md5(source)
+      if (actual !== info.md5) {
+        throw new Error(
+          `[UpdateSDK] Bundle MD5 mismatch for "${moduleId}": expected ${info.md5}, got ${actual}`,
+        )
+      }
+    }
+
     // 写入 AsyncStorage 缓存（版本记录）
     const cachePayload: CachedRnBundle = {
       moduleId,
diff --git a/packages/update/src/md5.ts b/packages/update/src/md5.ts
new file mode 100644
index 0000000..4467fc1
--- /dev/null
+++ b/packages/update/src/md5.ts
@@ -0,0 +1,127 @@
+/**
+ * Minimal MD5 implementation for bundle integrity verification.
+ * Based on the RSA Data Security, Inc. MD5 Message-Digest Algorithm (RFC 1321).
+ */
+
+function _ff(a: number, b: number, c: number, d: number, x: number, s: number, ac: number): number {
+  a = (a + ((b & c) | (~b & d)) + x + ac) | 0
+  return (((a << s) | (a >>> (32 - s))) + b) | 0
+}
+
+function _gg(a: number, b: number, c: number, d: number, x: number, s: number, ac: number): number {
+  a = (a + ((b & d) | (c & ~d)) + x + ac) | 0
+  return (((a << s) | (a >>> (32 - s))) + b) | 0
+}
+
+function _hh(a: number, b: number, c: number, d: number, x: number, s: number, ac: number): number {
+  a = (a + (b ^ c ^ d) + x + ac) | 0
+  return (((a << s) | (a >>> (32 - s))) + b) | 0
+}
+
+function _ii(a: number, b: number, c: number, d: number, x: number, s: number, ac: number): number {
+  a = (a + (c ^ (b | ~d)) + x + ac) | 0
+  return (((a << s) | (a >>> (32 - s))) + b) | 0
+}
+
+function _toWords(input: string): number[] {
+  const msg = unescape(encodeURIComponent(input))
+  const len = msg.length
+  const n = (((len + 8) >>> 6) << 4) + 16
+  const words = new Array<number>(n).fill(0)
+  for (let i = 0; i < len; i++) {
+    words[i >> 2] |= (msg.charCodeAt(i) & 0xff) << ((i % 4) << 3)
+  }
+  words[len >> 2] |= 0x80 << ((len % 4) << 3)
+  words[n - 2] = len << 3
+  return words
+}
+
+function _hex(n: number): string {
+  let s = ''
+  for (let j = 0; j < 4; j++) {
+    s += '0123456789abcdef'.charAt((n >> (j * 8 + 4)) & 0x0f) +
+         '0123456789abcdef'.charAt((n >> (j * 8)) & 0x0f)
+  }
+  return s
+}
+
+export function md5(input: string): string {
+  const x = _toWords(input)
+  let a = 0x67452301, b = 0xefcdab89, c = 0x98badcfe, d = 0x10325476
+
+  for (let i = 0; i < x.length; i += 16) {
+    const oa = a, ob = b, oc = c, od = d
+
+    a = _ff(a, b, c, d, x[i],      7, 0xd76aa478)
+    d = _ff(d, a, b, c, x[i + 1],  12, 0xe8c7b756)
+    c = _ff(c, d, a, b, x[i + 2], 17, 0x242070db)
+    b = _ff(b, c, d, a, x[i + 3], 22, 0xc1bdceee)
+    a = _ff(a, b, c, d, x[i + 4],  7, 0xf57c0faf)
+    d = _ff(d, a, b, c, x[i + 5], 12, 0x4787c62a)
+    c = _ff(c, d, a, b, x[i + 6], 17, 0xa8304613)
+    b = _ff(b, c, d, a, x[i + 7], 22, 0xfd469501)
+    a = _ff(a, b, c, d, x[i + 8],  7, 0x698098d8)
+    d = _ff(d, a, b, c, x[i + 9], 12, 0x8b44f7af)
+    c = _ff(c, d, a, b, x[i + 10],17, 0xffff5bb1)
+    b = _ff(b, c, d, a, x[i + 11],22, 0x895cd7be)
+    a = _ff(a, b, c, d, x[i + 12], 7, 0x6b901122)
+    d = _ff(d, a, b, c, x[i + 13],12, 0xfd987193)
+    c = _ff(c, d, a, b, x[i + 14],17, 0xa679438e)
+    b = _ff(b, c, d, a, x[i + 15],22, 0x49b40821)
+
+    a = _gg(a, b, c, d, x[i + 1],  5, 0xf61e2562)
+    d = _gg(d, a, b, c, x[i + 6],  9, 0xc040b340)
+    c = _gg(c, d, a, b, x[i + 11],14, 0x265e5a51)
+    b = _gg(b, c, d, a, x[i],     20, 0xe9b6c7aa)
+    a = _gg(a, b, c, d, x[i + 5],  5, 0xd62f105d)
+    d = _gg(d, a, b, c, x[i + 10], 9, 0x02441453)
+    c = _gg(c, d, a, b, x[i + 15],14, 0xd8a1e681)
+    b = _gg(b, c, d, a, x[i + 4], 20, 0xe7d3fbc8)
+    a = _gg(a, b, c, d, x[i + 9],  5, 0x21e1cde6)
+    d = _gg(d, a, b, c, x[i + 14], 9, 0xc33707d6)
+    c = _gg(c, d, a, b, x[i + 3], 14, 0xf4d50d87)
+    b = _gg(b, c, d, a, x[i + 8], 20, 0x455a14ed)
+    a = _gg(a, b, c, d, x[i + 13], 5, 0xa9e3e905)
+    d = _gg(d, a, b, c, x[i + 2],  9, 0xfcefa3f8)
+    c = _gg(c, d, a, b, x[i + 7], 14, 0x676f02d9)
+    b = _gg(b, c, d, a, x[i + 12],20, 0x8d2a4c8a)
+
+    a = _hh(a, b, c, d, x[i + 5],  4, 0xfffa3942)
+    d = _hh(d, a, b, c, x[i + 8], 11, 0x8771f681)
+    c = _hh(c, d, a, b, x[i + 11],16, 0x6d9d6122)
+    b = _hh(b, c, d, a, x[i + 14],23, 0xfde5380c)
+    a = _hh(a, b, c, d, x[i + 1],  4, 0xa4beea44)
+    d = _hh(d, a, b, c, x[i + 4], 11, 0x4bdecfa9)
+    c = _hh(c, d, a, b, x[i + 7], 16, 0xf6bb4b60)
+    b = _hh(b, c, d, a, x[i + 10],23, 0xbebfbc70)
+    a = _hh(a, b, c, d, x[i + 13], 4, 0x289b7ec6)
+    d = _hh(d, a, b, c, x[i],     11, 0xeaa127fa)
+    c = _hh(c, d, a, b, x[i + 3], 16, 0xd4ef3085)
+    b = _hh(b, c, d, a, x[i + 6], 23, 0x04881d05)
+    a = _hh(a, b, c, d, x[i + 9],  4, 0xd9d4d039)
+    d = _hh(d, a, b, c, x[i + 12],11, 0xe6db99e5)
+    c = _hh(c, d, a, b, x[i + 15],16, 0x1fa27cf8)
+    b = _hh(b, c, d, a, x[i + 2], 23, 0xc4ac5665)
+
+    a = _ii(a, b, c, d, x[i],      6, 0xf4292244)
+    d = _ii(d, a, b, c, x[i + 7], 10, 0x432aff97)
+    c = _ii(c, d, a, b, x[i + 14],15, 0xab9423a7)
+    b = _ii(b, c, d, a, x[i + 5], 21, 0xfc93a039)
+    a = _ii(a, b, c, d, x[i + 12], 6, 0x655b59c3)
+    d = _ii(d, a, b, c, x[i + 3], 10, 0x8f0ccc92)
+    c = _ii(c, d, a, b, x[i + 10],15, 0xffeff47d)
+    b = _ii(b, c, d, a, x[i + 1], 21, 0x85845dd1)
+    a = _ii(a, b, c, d, x[i + 8],  6, 0x6fa87e4f)
+    d = _ii(d, a, b, c, x[i + 15],10, 0xfe2ce6e0)
+    c = _ii(c, d, a, b, x[i + 6], 15, 0xa3014314)
+    b = _ii(b, c, d, a, x[i + 13],21, 0x4e0811a1)
+    a = _ii(a, b, c, d, x[i + 4],  6, 0xf7537e82)
+    d = _ii(d, a, b, c, x[i + 11],10, 0xbd3af235)
+    c = _ii(c, d, a, b, x[i + 2], 15, 0x2ad7d2bb)
+    b = _ii(b, c, d, a, x[i + 9], 21, 0xeb86d391)
+
+    a = (a + oa) | 0; b = (b + ob) | 0; c = (c + oc) | 0; d = (d + od) | 0
+  }
+
+  return _hex(a) + _hex(b) + _hex(c) + _hex(d)
+}