diff --git a/lib/fetchSubtitle.ts b/lib/fetchSubtitle.ts
index 8bf21690..75d0d8f1 100644
--- a/lib/fetchSubtitle.ts
+++ b/lib/fetchSubtitle.ts
@@ -1,5 +1,5 @@
-import { VideoService } from "./types";
 import { fetchBilibiliSubtitle } from "./bilibili/fetchBilibiliSubtitle";
+import { CommonSubtitleItem, VideoService } from "./types";
 import { fetchYoutubeSubtitle } from "./youtube/fetchYoutubeSubtitle";
 
 export async function fetchSubtitle(
@@ -8,7 +8,7 @@ export async function fetchSubtitle(
   shouldShowTimestamp?: boolean
 ): Promise<{
   title: string;
-  subtitlesArray?: null | Array<{ index: number; text: string }>;
+  subtitlesArray?: null | Array<CommonSubtitleItem>;
   descriptionText?: string;
 }> {
   if (service === VideoService.Youtube) {
diff --git a/lib/types.ts b/lib/types.ts
index 97b3a629..0aaa9197 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -21,3 +21,5 @@ export enum VideoService {
   LocalVideo = "local-video",
   LocalAudio = "local-audio",
 }
+
+export type CommonSubtitleItem = { text: string; index: number };
diff --git a/lib/youtube/fetchYoutubeSubtitle.ts b/lib/youtube/fetchYoutubeSubtitle.ts
index b831255e..ce2fd01e 100644
--- a/lib/youtube/fetchYoutubeSubtitle.ts
+++ b/lib/youtube/fetchYoutubeSubtitle.ts
@@ -1,5 +1,6 @@
 import { fetchYoutubeSubtitleUrls, SUBTITLE_DOWNLOADER_URL } from "~/lib/youtube/fetchYoutubeSubtitleUrls";
 import { find } from "~/utils/fp";
+import { reduceSubtitleTimestamp } from "~/utils/reduceSubtitleTimestamp";
 
 export async function fetchYoutubeSubtitle(
   videoId: string,
@@ -10,22 +11,16 @@ export async function fetchYoutubeSubtitle(
     return { title, subtitlesArray: null };
   }
   const betterSubtitle =
+    find(subtitleList, { quality: "zh-CN" }) ||
     find(subtitleList, { quality: "English" }) ||
     find(subtitleList, { quality: "English (auto" }) ||
-    find(subtitleList, { quality: "zh-CN" }) ||
     subtitleList[0];
   if (shouldShowTimestamp) {
     const subtitleUrl = `${SUBTITLE_DOWNLOADER_URL}${betterSubtitle.url}?ext=json`;
     const response = await fetch(subtitleUrl);
     const subtitles = await response.json();
     // console.log("========subtitles========", subtitles);
-    // TODO: merge timestamp by trunk
-    const transcripts = subtitles?.map(
-      (item: { start: number; lines: string[] }, index: number) => ({
-        text: `${item.start}: ${item.lines.join(" ")}`,
-        index
-      })
-    );
+    const transcripts = reduceSubtitleTimestamp(subtitles);
     return { title, subtitlesArray: transcripts };
   }
 
diff --git a/middleware.ts b/middleware.ts
index 566194cd..e3480995 100644
--- a/middleware.ts
+++ b/middleware.ts
@@ -40,7 +40,7 @@ export async function middleware(req: NextRequest, context: NextFetchEvent) {
     }
 
     if (!userKey) {
-      const identifier = req.ip ?? "127.0.0.8";
+      const identifier = req.ip ?? "127.0.0.10";
       const { success, remaining } = await ratelimitForIps.limit(identifier);
       console.log(
         `======== ip ${identifier}, remaining: ${remaining} ========`
diff --git a/utils/reduceSubtitleTimestamp.ts b/utils/reduceSubtitleTimestamp.ts
new file mode 100644
index 00000000..c95f372a
--- /dev/null
+++ b/utils/reduceSubtitleTimestamp.ts
@@ -0,0 +1,42 @@
+import { CommonSubtitleItem } from "~/lib/types";
+
+export type YoutubeSubtitleItem = { start: number; lines: string[] };
+
+export function reduceSubtitleTimestamp(
+  subtitles: Array<YoutubeSubtitleItem>
+): Array<CommonSubtitleItem> {
+  // 把字幕数组分成 10 组
+  const groupCount = 20;
+  const eachGroupCount =
+    subtitles.length > groupCount
+      ? subtitles.length / groupCount
+      : subtitles.length;
+
+  return subtitles.reduce(
+    (
+      accumulator: CommonSubtitleItem[],
+      current: YoutubeSubtitleItem,
+      index: number
+    ) => {
+      // 计算当前元素在哪一组
+      const groupIndex: number = Math.floor(index / eachGroupCount);
+
+      // 如果是当前组的第一个元素，初始化这一组的字符串
+      if (!accumulator[groupIndex]) {
+        accumulator[groupIndex] = {
+          // 5.88 -> 5.9
+          // text: current.start.toFixed() + ": ",
+          text: current.start + ": ",
+          index: groupIndex,
+        };
+      }
+
+      // 将当前元素添加到当前组的字符串末尾
+      accumulator[groupIndex].text =
+        accumulator[groupIndex].text + current.lines.join(" ") + " ";
+
+      return accumulator;
+    },
+    []
+  );
+}