diff --git a/src/client/OicqClient.ts b/src/client/OicqClient.ts
index 04459a9..e9cbfc1 100644
--- a/src/client/OicqClient.ts
+++ b/src/client/OicqClient.ts
@@ -13,8 +13,8 @@ import { execSync } from 'child_process';
 import random from '../utils/random';
 import fs from 'fs';
 import fsP from 'fs/promises';
-import path from 'path';
 import { Config } from 'oicq/lib/client';
+import dataPath from '../helpers/dataPath';
 
 const LOG_LEVEL: LogLevel = 'warn';
 
@@ -77,8 +77,8 @@ export default class OicqClient extends Client {
         resolve(client);
       }
 
-      if (!fs.existsSync(`./data/${params.uin}/device-${params.uin}.json`)) {
-        await fsP.mkdir(`./data/${params.uin}`, { recursive: true });
+      if (!fs.existsSync(dataPath(`${params.uin}/device-${params.uin}.json`))) {
+        await fsP.mkdir(dataPath(params.uin.toString()), { recursive: true });
 
         const device = {
           product: 'Q2TG',
@@ -97,12 +97,12 @@ export default class OicqClient extends Client {
           imei: random.imei(),
         };
 
-        await fsP.writeFile(`./data/${params.uin}/device-${params.uin}.json`, JSON.stringify(device, null, 0), 'utf-8');
+        await fsP.writeFile(dataPath(`${params.uin}/device-${params.uin}.json`), JSON.stringify(device, null, 0), 'utf-8');
       }
 
       const client = new this(params.uin, {
         platform: params.platform,
-        data_dir: path.resolve('./data'),
+        data_dir: dataPath(),
         log_level: LOG_LEVEL,
         ffmpeg_path: process.env.FFMPEG_PATH,
         ffprobe_path: process.env.FFPROBE_PATH,
diff --git a/src/helpers/convert.ts b/src/helpers/convert.ts
new file mode 100644
index 0000000..fc4f236
--- /dev/null
+++ b/src/helpers/convert.ts
@@ -0,0 +1,42 @@
+import dataPath from './dataPath';
+import fs from 'fs';
+import path from 'path';
+import sharp from 'sharp';
+import { file as createTempFile } from 'tmp-promise';
+import fsP from 'fs/promises';
+import convertWithFfmpeg from '../encoding/convertWithFfmpeg';
+import tgsToGif from '../encoding/tgsToGif';
+
+const CACHE_PATH = dataPath('cache');
+fs.mkdirSync(CACHE_PATH, { recursive: true });
+
+// 首先查找缓存，要是缓存中没有的话执行第二个参数的方法转换到缓存的文件
+const cachedConvert = async (key: string, convert: (outputPath: string) => Promise<any>) => {
+  const convertedPath = path.join(CACHE_PATH, key);
+  if (!fs.existsSync(convertedPath)) {
+    await convert(convertedPath);
+  }
+  return convertedPath;
+};
+
+export default {
+  // webp2png，这里 webpData 是方法因为不需要的话就不获取了
+  png: (key: string, webpData: () => Promise<Buffer | Uint8Array | string>) =>
+    cachedConvert(key + '.png', async (convertedPath) => {
+      await sharp(await webpData()).png().toFile(convertedPath);
+    }),
+  webm2gif: (key: string, webmData: () => Promise<Buffer | Uint8Array | string>) =>
+    cachedConvert(key + '.gif', async (convertedPath) => {
+      const temp = await createTempFile();
+      await fsP.writeFile(temp.path, await webmData());
+      await convertWithFfmpeg(temp.path, convertedPath, 'gif');
+      await temp.cleanup();
+    }),
+  tgs2gif: (key: string, tgsData: () => Promise<Buffer | Uint8Array | string>) =>
+    cachedConvert(key + '.gif', async (convertedPath) => {
+      const tempTgsPath = path.join(CACHE_PATH, key);
+      await fsP.writeFile(tempTgsPath, await tgsData());
+      await tgsToGif(tempTgsPath);
+      await fsP.rm(tempTgsPath);
+    }),
+};
diff --git a/src/helpers/dataPath.ts b/src/helpers/dataPath.ts
new file mode 100644
index 0000000..9fd5ec0
--- /dev/null
+++ b/src/helpers/dataPath.ts
@@ -0,0 +1,7 @@
+import path from 'path';
+
+const DATA_DIR = process.env.DATA_DIR || path.resolve('./data');
+
+// Wrap of path.join, add base DATA_DIR
+export default (...paths: string[]) =>
+  path.join(DATA_DIR, ...paths);
diff --git a/src/index.ts b/src/index.ts
index edfd5ea..8c2a855 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -3,7 +3,6 @@ import Instance from './models/Instance';
 import db from './models/db';
 
 (async () => {
-  process.env.DATA_DIR && process.chdir(process.env.DATA_DIR);
   configure({
     appenders: {
       console: { type: 'console' },
diff --git a/src/services/ForwardService.ts b/src/services/ForwardService.ts
index 2285b36..bf49650 100644
--- a/src/services/ForwardService.ts
+++ b/src/services/ForwardService.ts
@@ -15,18 +15,15 @@ import { file as createTempFile, FileResult } from 'tmp-promise';
 import fsP from 'fs/promises';
 import eviltransform from 'eviltransform';
 import silk from '../encoding/silk';
-import fs from 'fs';
-import tgsToGif from '../encoding/tgsToGif';
 import axios from 'axios';
 import { md5Hex } from '../utils/hashing';
 import Instance from '../models/Instance';
 import { Pair } from '../models/Pair';
-import sharp from 'sharp';
-import convertWithFfmpeg from '../encoding/convertWithFfmpeg';
 import OicqClient from '../client/OicqClient';
 import lottie from '../constants/lottie';
 import _ from 'lodash';
 import emoji from '../constants/emoji';
+import convert from '../helpers/convert';
 
 const NOT_CHAINABLE_ELEMENTS = ['flash', 'record', 'video', 'location', 'share', 'json', 'xml', 'poke'];
 
@@ -291,13 +288,7 @@ export default class ForwardService {
         message.document?.mimeType?.startsWith('image/')) {
         // 将 webp 转换为 png，防止 macOS 不识别
         if (message.document?.mimeType === 'image/webp') {
-          const convertedPath = path.resolve(path.join('./data/cache/webp', message.document.id.toString(16) + '.png'));
-          // 先从缓存中找
-          if (!fs.existsSync(convertedPath)) {
-            await fsP.mkdir('./data/cache/webp', { recursive: true });
-            const webpData = await message.downloadMedia({});
-            await sharp(webpData).png().toFile(convertedPath);
-          }
+          const convertedPath = await convert.png(message.document.id.toString(16), () => message.downloadMedia({}));
           chain.push({
             type: 'image',
             file: convertedPath,
@@ -320,15 +311,7 @@ export default class ForwardService {
         }
         else if (file.mimeType === 'video/webm' || message.gif) {
           // 把 webm 转换成 gif
-          const convertedPath = path.resolve(path.join('./data/cache/webm', message.document.id.toString(16) + '.gif'));
-          // 先从缓存中找
-          if (!fs.existsSync(convertedPath)) {
-            await fsP.mkdir('./data/cache/webm', { recursive: true });
-            const temp = await createTempFile();
-            tempFiles.push(temp);
-            await fsP.writeFile(temp.path, await message.downloadMedia({}));
-            await convertWithFfmpeg(temp.path, convertedPath, 'gif');
-          }
+          const convertedPath = await convert.webm2gif(message.document.id.toString(16), () => message.downloadMedia({}));
           chain.push({
             type: 'image',
             file: convertedPath,
@@ -345,19 +328,7 @@ export default class ForwardService {
       }
       else if (message.sticker) {
         // 一定是 tgs
-        let gifPath: string;
-        const tempTgsPath = path.resolve(path.join('./data/cache/tgs', message.sticker.id.toString(16)));
-        // 先从缓存中找
-        if (fs.existsSync(tempTgsPath + '.gif')) {
-          gifPath = tempTgsPath + '.gif';
-        }
-        else {
-          await fsP.mkdir('./data/cache/tgs', { recursive: true });
-          await fsP.writeFile(tempTgsPath, await message.downloadMedia({}));
-          await tgsToGif(tempTgsPath);
-          await fsP.rm(tempTgsPath);
-          gifPath = tempTgsPath + '.gif';
-        }
+        const gifPath = await convert.tgs2gif(message.sticker.id.toString(16), () => message.downloadMedia({}));
         chain.push({
           type: 'image',
           file: gifPath,