diff --git a/mobile-uni/src/services/speech-audio-source.ts b/mobile-uni/src/services/speech-audio-source.ts
index 9464a523..3d970a69 100644
--- a/mobile-uni/src/services/speech-audio-source.ts
+++ b/mobile-uni/src/services/speech-audio-source.ts
@@ -11,10 +11,29 @@ export interface DecodedAudioDataUri {
   bytes: Uint8Array;
 }
 
+/**
+ * App 端临时音频的两个路径缺一不可:
+ * - `playbackUrl` 是 convertLocalFileSystemURL 转出的 file:// 绝对路径,InnerAudioContext 只认这个;
+ * - `plusPath` 是 `_doc/xxx.mp3` 相对路径,resolveLocalFileSystemURL 删除时只认这个。
+ * 早前只回传前者,清理时拿绝对路径去 resolve 解析不到,remove() 从不执行,文件逐句堆积。
+ */
+export interface NativeTempAudio {
+  playbackUrl: string;
+  plusPath: string;
+}
+
 const DATA_AUDIO_URI_PATTERN = /^data:(audio\/[\w.+-]+);base64,([A-Za-z0-9+/=\r\n]+)$/i;
 
 export const isDataAudioUri = (source: string) => DATA_AUDIO_URI_PATTERN.test(source);
 
+/** 取出 base64 载荷,供 App 端 `writeAsBinary` 直接写入,无需 atob/Blob。 */
+export const extractAudioBase64 = (dataUri: string): { mime: string; base64: string } | null => {
+  const match = DATA_AUDIO_URI_PATTERN.exec(dataUri);
+  if (!match) return null;
+  const base64 = match[2].replace(/[\r\n]/g, '');
+  return base64 ? { mime: match[1], base64 } : null;
+};
+
 /** 纯解析,不依赖浏览器 API,便于单测。base64 非法或不是音频 data URI 时返回 null。 */
 export const decodeDataAudioUri = (dataUri: string): DecodedAudioDataUri | null => {
   const match = DATA_AUDIO_URI_PATTERN.exec(dataUri);
@@ -42,13 +61,20 @@ export const dataUriToBlobUrl = (dataUri: string): string | null => {
 interface PlusIoFileEntry {
   fullPath: string;
   createWriter: (ok: (writer: PlusIoWriter) => void, fail?: (err: unknown) => void) => void;
+  file: (ok: (meta: PlusIoFileMeta) => void, fail?: (err: unknown) => void) => void;
   remove: (ok?: () => void, fail?: (err: unknown) => void) => void;
 }
 
 interface PlusIoWriter {
   onwriteend: (() => void) | null;
   onerror: ((err: unknown) => void) | null;
-  write: (data: Blob) => void;
+  // plus.io 的 FileWriter 只接受字符串:write 写文本,writeAsBinary 收 base64。
+  // 传 Blob 会被原生桥接序列化成空内容,落地 0 字节且照样回调 onwriteend。
+  writeAsBinary: (data: string) => void;
+}
+
+interface PlusIoFileMeta {
+  size: number;
 }
 
 interface PlusIoDirectoryEntry {
@@ -77,20 +103,35 @@ const resolvePlusIo = (): PlusIo | null => {
 /** 是否处于需要落盘播放的 App-Plus 原生环境(避免与 speech-capture 循环引用,本地判定)。 */
 export const hasNativeAudioFileSupport = () => resolvePlusIo() !== null;
 
-/** App-Plus:base64 落 `_doc/` 临时文件,返回可播放的 file:// 路径;失败返回 null。 */
-export const writeNativeTempAudio = (dataUri: string): Promise<string | null> => {
-  const decoded = decodeDataAudioUri(dataUri);
+/**
+ * App-Plus:base64 落 `_doc/` 临时文件,返回可播放的 file:// 路径;失败返回 null。
+ *
+ * 写入后必须复核 `size > 0`:`onwriteend` 会在实际写了 0 字节时照样回调,
+ * 空文件交给 InnerAudioContext 会静默播完、不触发 onError,表现为"界面正常
+ * 但没有声音"。非空校验是这条链路唯一能暴露写盘失败的地方。
+ */
+export const writeNativeTempAudio = (dataUri: string): Promise<NativeTempAudio | null> => {
+  const payload = extractAudioBase64(dataUri);
   const io = resolvePlusIo();
-  if (!decoded || !io) return Promise.resolve(null);
+  if (!payload || !io) return Promise.resolve(null);
   return new Promise((resolve) => {
     try {
       io.resolveLocalFileSystemURL('_doc/', (dir) => {
         dir.getFile(`aihr-tts-${Date.now()}.mp3`, { create: true }, (fileEntry) => {
           fileEntry.createWriter((writer) => {
-            writer.onwriteend = () => resolve(io.convertLocalFileSystemURL(fileEntry.fullPath));
+            writer.onwriteend = () => {
+              fileEntry.file(
+                (meta) => resolve(meta && meta.size > 0
+                  ? {
+                    playbackUrl: io.convertLocalFileSystemURL(fileEntry.fullPath),
+                    plusPath: fileEntry.fullPath
+                  }
+                  : null),
+                () => resolve(null)
+              );
+            };
             writer.onerror = () => resolve(null);
-            const blobBytes = new Uint8Array(decoded.bytes);
-            writer.write(new Blob([blobBytes], { type: decoded.mime }));
+            writer.writeAsBinary(payload.base64);
           }, () => resolve(null));
         }, () => resolve(null));
       }, () => resolve(null));
@@ -100,13 +141,20 @@ export const writeNativeTempAudio = (dataUri: string): Promise<string | null> =>
   });
 };
 
-/** 播放结束后清理 App 端临时文件,尽力而为。 */
-export const removeNativeTempAudio = (fileUrl: string) => {
+/**
+ * 播放结束后清理 App 端临时文件,尽力而为。
+ * 入参必须是 `_doc/xxx.mp3` 形式的 plus 路径,不能传 file:// 绝对路径,否则解析不到。
+ */
+export const removeNativeTempAudio = (plusPath: string) => {
   const io = resolvePlusIo();
-  if (!io) return;
+  if (!io || !plusPath) return;
   try {
-    io.resolveLocalFileSystemURL(fileUrl, (entry) => entry.remove());
-  } catch {
-    // 清理失败不影响播放主流程
+    io.resolveLocalFileSystemURL(
+      plusPath,
+      (entry) => entry.remove(undefined, (err) => console.warn('[tts] 临时音频删除失败', plusPath, err)),
+      (err) => console.warn('[tts] 临时音频路径解析失败', plusPath, err)
+    );
+  } catch (err) {
+    console.warn('[tts] 临时音频清理异常', plusPath, err);
   }
 };
diff --git a/mobile-uni/src/services/speech.ts b/mobile-uni/src/services/speech.ts
index 0f2cc71d..47bece63 100644
--- a/mobile-uni/src/services/speech.ts
+++ b/mobile-uni/src/services/speech.ts
@@ -245,16 +245,16 @@ export const createSpeechPlaybackController = (
     // webview 也常静默失败,统一先转换:H5 转 Blob URL,App 端落临时文件。
     if (isDataAudioUri(source)) {
       if (hasNativeAudioFileSupport()) {
-        void writeNativeTempAudio(source).then((fileUrl) => {
-          if (!fileUrl) {
+        void writeNativeTempAudio(source).then((temp) => {
+          if (!temp) {
             failPlayback();
             return;
           }
           if (!isActivePlayback()) {
-            removeNativeTempAudio(fileUrl);
+            removeNativeTempAudio(temp.plusPath);
             return;
           }
-          startPlayback(fileUrl, () => removeNativeTempAudio(fileUrl));
+          startPlayback(temp.playbackUrl, () => removeNativeTempAudio(temp.plusPath));
         });
         return;
       }
diff --git a/mobile-uni/tests/speech-audio-source.test.mjs b/mobile-uni/tests/speech-audio-source.test.mjs
index 87c1829d..3ddeedc4 100644
Binary files a/mobile-uni/tests/speech-audio-source.test.mjs and b/mobile-uni/tests/speech-audio-source.test.mjs differ