diff --git a/addon/content/preferences.xhtml b/addon/content/preferences.xhtml
index 5e3f456..4443a0c 100644
--- a/addon/content/preferences.xhtml
+++ b/addon/content/preferences.xhtml
@@ -177,6 +177,23 @@
       preference="mineruPath"
     ></html:input>
   </hbox>
+
+  <hbox align="center">
+    <html:label
+      for="chatpapers-pref-lecture-data-dir"
+      data-l10n-id="prefs-lecture-data-dir"
+    ></html:label>
+    <html:input
+      type="text"
+      id="chatpapers-pref-lecture-data-dir"
+      preference="lectureDataDir"
+    ></html:input>
+  </hbox>
+  <html:p
+    id="chatpapers-pref-lecture-data-dir-hint"
+    class="chatpapers-pref-hint"
+    data-l10n-id="prefs-lecture-data-dir-hint"
+  ></html:p>
 </groupbox>
 
 <groupbox>
diff --git a/addon/locale/en-US/addon.ftl b/addon/locale/en-US/addon.ftl
index d3f3d7c..29590db 100644
--- a/addon/locale/en-US/addon.ftl
+++ b/addon/locale/en-US/addon.ftl
@@ -135,3 +135,4 @@ lecture-tts-provider = TTS: { $provider }
 lecture-tts-test = Test voice
 lecture-tts-testing = Synthesizing test speech…
 lecture-tts-test-done = Speech ready — playing
+lecture-storage-write-failed = Cannot write voice lecture data to { $path }. { $detail } Set “Data directory” under Edit → Settings → ChatPapers → Voice lecture (must be writable).
diff --git a/addon/locale/en-US/preferences.ftl b/addon/locale/en-US/preferences.ftl
index 4586908..25576fc 100644
--- a/addon/locale/en-US/preferences.ftl
+++ b/addon/locale/en-US/preferences.ftl
@@ -34,4 +34,6 @@ prefs-tts-voice = Voice (optional)
 prefs-piper-path = Piper executable
 prefs-piper-model = Piper model path (.onnx)
 prefs-mineru-path = MinerU path
+prefs-lecture-data-dir = Data directory
+prefs-lecture-data-dir-hint = Leave empty to use chatpapers/lecture under your Zotero profile. If writes fail, set a writable absolute path, e.g. D:\ChatPapers\lecture-data
 prefs-tts-hint-empty = Choose a TTS engine. Local engines are fully offline — no API key needed.
diff --git a/addon/locale/zh-CN/addon.ftl b/addon/locale/zh-CN/addon.ftl
index d7ebf13..a2ef57d 100644
--- a/addon/locale/zh-CN/addon.ftl
+++ b/addon/locale/zh-CN/addon.ftl
@@ -135,3 +135,4 @@ lecture-tts-provider = TTS 引擎：{ $provider }
 lecture-tts-test = 试听语音
 lecture-tts-testing = 正在合成测试语音…
 lecture-tts-test-done = 语音合成完成，正在播放
+lecture-storage-write-failed = 无法写入语音伴读数据目录：{ $path }。{ $detail } 请在 编辑 → 设置 → ChatPapers → 语音伴读 中配置「数据存储目录」（需有写入权限）。
diff --git a/addon/locale/zh-CN/preferences.ftl b/addon/locale/zh-CN/preferences.ftl
index 8d950a3..1603f19 100644
--- a/addon/locale/zh-CN/preferences.ftl
+++ b/addon/locale/zh-CN/preferences.ftl
@@ -34,4 +34,6 @@ prefs-tts-voice = 音色（可选）
 prefs-piper-path = Piper 可执行文件
 prefs-piper-model = Piper 模型路径 (.onnx)
 prefs-mineru-path = MinerU 路径
+prefs-lecture-data-dir = 数据存储目录
+prefs-lecture-data-dir-hint = 留空则使用 Zotero 配置文件夹下的 chatpapers/lecture。若写入失败，请填写有写入权限的绝对路径，例如 D:\ChatPapers\lecture-data
 prefs-tts-hint-empty = 请选择 TTS 引擎。本地引擎完全离线，无需 API Key。
diff --git a/addon/prefs.js b/addon/prefs.js
index d9540e9..7fa47c5 100644
--- a/addon/prefs.js
+++ b/addon/prefs.js
@@ -20,5 +20,6 @@ pref("lectureTeacherStyle", "balanced");
 pref("mineruPath", "");
 pref("piperPath", "");
 pref("piperModelPath", "");
+pref("lectureDataDir", "");
 pref("chatPaneAdaptiveHeight", true);
 pref("lecturePaneAdaptiveHeight", true);
diff --git a/src/modules/lecture/infrastructure/platform/paths.ts b/src/modules/lecture/infrastructure/platform/paths.ts
index f4f40ca..c3a167e 100644
--- a/src/modules/lecture/infrastructure/platform/paths.ts
+++ b/src/modules/lecture/infrastructure/platform/paths.ts
@@ -22,6 +22,43 @@ export function joinPath(...parts: string[]): string {
   return PathUtils.join(...parts.filter(Boolean));
 }
 
+/** Normalize a filesystem path for the current OS. */
+export function normalizeStoragePath(input: string): string {
+  const trimmed = (input || "").trim();
+  if (!trimmed) return "";
+  const joined = trimmed.replace(/[\\/]+/g, "/");
+  if (/^[A-Za-z]:\//.test(joined)) {
+    const drive = joined.slice(0, 2);
+    const rest = joined
+      .slice(2)
+      .split("/")
+      .filter((part) => part && part !== ".")
+      .join("\\");
+    return `${drive}\\${rest}`.replace(/\\+$/, "");
+  }
+  return joined
+    .split("/")
+    .filter((part) => part && part !== ".")
+    .join("/")
+    .replace(/\/+$/, "");
+}
+
+/** Safe single path segment for file or directory names (cross-platform). */
+export function sanitizePathSegment(input: string, maxLen = 120): string {
+  const cleaned = String(input || "")
+    .replace(/[<>:"/\\|?*\x00-\x1f]/g, "_")
+    .replace(/[.\s]+$/, "")
+    .trim();
+  if (!cleaned) return "_";
+  if (cleaned.length <= maxLen) return cleaned;
+  let hash = 0;
+  for (let i = 0; i < input.length; i++) {
+    hash = (hash * 31 + input.charCodeAt(i)) | 0;
+  }
+  const tail = Math.abs(hash).toString(36);
+  return `${cleaned.slice(0, Math.max(1, maxLen - tail.length - 1))}_${tail}`;
+}
+
 /** Convert local file path to file:// URL for <audio src>. */
 export function pathToFileUrl(filePath: string): string {
   const normalized = filePath.replace(/\\/g, "/");
diff --git a/src/modules/lecture/infrastructure/storage/lectureStore.ts b/src/modules/lecture/infrastructure/storage/lectureStore.ts
index 791cd01..ada5fc3 100644
--- a/src/modules/lecture/infrastructure/storage/lectureStore.ts
+++ b/src/modules/lecture/infrastructure/storage/lectureStore.ts
@@ -1,7 +1,9 @@
 import type { BeatType, SummaryJson } from "../../domain/types";
 import type { TextChunk } from "../pdf/chunker";
-import { joinPath } from "../platform/paths";
-import { ensureLectureDirs, lectureDataRoot } from "./paths";
+import {
+  ensureLectureDirs,
+  lectureDataFilePath,
+} from "./paths";
 
 export interface StoredBeat {
   id: string;
@@ -73,8 +75,7 @@ export interface LectureData {
 }
 
 function lectureDataPath(cacheKey: string): string {
-  const safe = cacheKey.replace(/[^a-zA-Z0-9_|.-]/g, "_");
-  return joinPath(lectureDataRoot(), "data", `${safe}.json`);
+  return lectureDataFilePath(cacheKey);
 }
 
 export async function loadLectureData(
@@ -94,11 +95,6 @@ export async function loadLectureData(
 
 export async function saveLectureData(data: LectureData): Promise<void> {
   await ensureLectureDirs();
-  const dir = joinPath(lectureDataRoot(), "data");
-  await IOUtils.makeDirectory(dir, {
-    createAncestors: true,
-    ignoreExisting: true,
-  });
   data.updatedAt = Date.now();
   await IOUtils.writeUTF8(
     lectureDataPath(data.cacheKey),
diff --git a/src/modules/lecture/infrastructure/storage/paths.ts b/src/modules/lecture/infrastructure/storage/paths.ts
index d532d7f..9bd2350 100644
--- a/src/modules/lecture/infrastructure/storage/paths.ts
+++ b/src/modules/lecture/infrastructure/storage/paths.ts
@@ -1,18 +1,50 @@
-import { joinPath } from "../platform/paths";
+import { getPref } from "../../../../utils/prefs";
+import { getString } from "../../../../utils/locale";
+import {
+  joinPath,
+  normalizeStoragePath,
+  sanitizePathSegment,
+} from "../platform/paths";
 
-function profileDir(): string {
-  const profile =
-    (Zotero as any).Profile?.dir ||
-    (Zotero as any).getProfileDirectory?.()?.path;
-  if (!profile) {
-    throw new Error("Cannot resolve Zotero profile directory");
+function resolveProfileDir(): string {
+  const z = Zotero as any;
+  const candidates: unknown[] = [
+    z.Profile?.dir,
+    typeof z.getProfileDirectory === "function" ? z.getProfileDirectory() : undefined,
+  ];
+
+  for (const candidate of candidates) {
+    const path =
+      typeof candidate === "string"
+        ? candidate
+        : candidate &&
+            typeof candidate === "object" &&
+            "path" in candidate &&
+            typeof (candidate as { path: unknown }).path === "string"
+          ? (candidate as { path: string }).path
+          : "";
+    if (path.trim()) return normalizeStoragePath(path.trim());
   }
-  return profile;
+
+  throw new Error("Cannot resolve Zotero profile directory");
 }
 
-/** `{Profile}/chatpapers/lecture/` — voice lecture data root */
+function customLectureDataDir(): string {
+  return String(getPref("lectureDataDir") || "").trim();
+}
+
+/** Map logical cacheKey (may contain `|`) to a filesystem-safe directory/file stem. */
+export function cacheKeyDirName(cacheKey: string): string {
+  return sanitizePathSegment(cacheKey, 100);
+}
+
+/** Resolved voice-lecture data root (custom pref or `{Profile}/chatpapers/lecture/`). */
 export function lectureDataRoot(): string {
-  return joinPath(profileDir(), "chatpapers", "lecture");
+  const custom = customLectureDataDir();
+  if (custom) {
+    return normalizeStoragePath(custom);
+  }
+  return joinPath(resolveProfileDir(), "chatpapers", "lecture");
 }
 
 export function lectureDbPath(): string {
@@ -24,12 +56,16 @@ export function lectureIndexPath(): string {
   return joinPath(lectureDataRoot(), "cache-index.json");
 }
 
+export function lectureDataFilePath(cacheKey: string): string {
+  return joinPath(lectureDataRoot(), "data", `${cacheKeyDirName(cacheKey)}.json`);
+}
+
 export function audioRootDir(): string {
   return joinPath(lectureDataRoot(), "audio");
 }
 
 export function audioDirForPaper(cacheKey: string): string {
-  return joinPath(audioRootDir(), cacheKey);
+  return joinPath(audioRootDir(), cacheKeyDirName(cacheKey));
 }
 
 export function audioFilePath(
@@ -37,30 +73,41 @@ export function audioFilePath(
   unitId: string,
   ext: "wav" | "mp3" = "wav",
 ): string {
-  return joinPath(audioDirForPaper(cacheKey), `${unitId}.${ext}`);
+  return joinPath(
+    audioDirForPaper(cacheKey),
+    `${sanitizePathSegment(unitId, 80)}.${ext}`,
+  );
 }
 
 export function lectureSamplePath(name: string): string {
-  return joinPath(lectureDataRoot(), "samples", name);
+  return joinPath(lectureDataRoot(), "samples", sanitizePathSegment(name, 80));
 }
 
 export async function ensureSampleDir(): Promise<string> {
   const dir = joinPath(lectureDataRoot(), "samples");
-  await IOUtils.makeDirectory(dir, {
+  await ensureDir(dir);
+  return dir;
+}
+
+async function ensureDir(path: string): Promise<void> {
+  await IOUtils.makeDirectory(path, {
     createAncestors: true,
     ignoreExisting: true,
   });
-  return dir;
 }
 
 export async function ensureLectureDirs(): Promise<void> {
   const root = lectureDataRoot();
-  await IOUtils.makeDirectory(root, {
-    createAncestors: true,
-    ignoreExisting: true,
-  });
-  await IOUtils.makeDirectory(audioRootDir(), {
-    createAncestors: true,
-    ignoreExisting: true,
-  });
+  try {
+    await ensureDir(root);
+    await ensureDir(joinPath(root, "data"));
+    await ensureDir(audioRootDir());
+  } catch (e) {
+    const detail = e instanceof Error ? e.message : String(e);
+    throw new Error(
+      getString("lecture-storage-write-failed", {
+        args: { path: root, detail },
+      }),
+    );
+  }
 }
diff --git a/src/modules/ui/lecturePrefs.ts b/src/modules/ui/lecturePrefs.ts
index 37b5a0c..d8bdd47 100644
--- a/src/modules/ui/lecturePrefs.ts
+++ b/src/modules/ui/lecturePrefs.ts
@@ -25,6 +25,9 @@ export function registerLecturePrefsScripts(win: Window) {
   const mineruPathInput = doc.getElementById(
     "chatpapers-pref-mineru-path",
   ) as HTMLInputElement | null;
+  const lectureDataDirInput = doc.getElementById(
+    "chatpapers-pref-lecture-data-dir",
+  ) as HTMLInputElement | null;
   const hint = doc.getElementById("chatpapers-pref-tts-hint");
   const piperBox = doc.getElementById("chatpapers-pref-piper-box");
 
@@ -83,5 +86,9 @@ export function registerLecturePrefsScripts(win: Window) {
     setPref("mineruPath", mineruPathInput.value);
   });
 
+  lectureDataDirInput?.addEventListener("change", () => {
+    setPref("lectureDataDir", lectureDataDirInput.value.trim());
+  });
+
   updateHint();
 }
diff --git a/typings/i10n.d.ts b/typings/i10n.d.ts
index 8612785..72cbbca 100644
--- a/typings/i10n.d.ts
+++ b/typings/i10n.d.ts
@@ -103,6 +103,7 @@ export type FluentMessageId =
   | 'lecture-status-ready-phase1'
   | 'lecture-status-ready-step1'
   | 'lecture-status-ready-step2'
+  | 'lecture-storage-write-failed'
   | 'lecture-tts-provider'
   | 'lecture-tts-test'
   | 'lecture-tts-test-done'
@@ -133,6 +134,8 @@ export type FluentMessageId =
   | 'prefs-hint-empty'
   | 'prefs-hint-local'
   | 'prefs-hint-openrouter'
+  | 'prefs-lecture-data-dir'
+  | 'prefs-lecture-data-dir-hint'
   | 'prefs-max-context'
   | 'prefs-max-tokens'
   | 'prefs-mineru-path'
diff --git a/typings/prefs.d.ts b/typings/prefs.d.ts
index ecf839f..1f4ad3d 100644
--- a/typings/prefs.d.ts
+++ b/typings/prefs.d.ts
@@ -29,6 +29,7 @@ declare namespace _ZoteroTypes {
       "mineruPath": string;
       "piperPath": string;
       "piperModelPath": string;
+      "lectureDataDir": string;
       "chatPaneAdaptiveHeight": boolean;
       "lecturePaneAdaptiveHeight": boolean;
     };