diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9cb849f..e11c544 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## Changelog
 
+* 2.9.9
+  - fixed trend file issue (#160)
+
 * 2.9.8
   - fixed wrong duration for shards (#157)
 
diff --git a/lib/index.js b/lib/index.js
index 762270c..508977e 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -1,3 +1,4 @@
+const fs = require('fs');
 const path = require('path');
 const EC = require('eight-colors');
 const { getSystemInfo, getTickInfo } = require('./utils/system.js');
@@ -95,8 +96,30 @@ class MonocartReporter {
     }
 
     cleanOutputDir() {
-        Util.initDir(this.options.outputDir);
-        // console.log('=========================== ', 'cleanOutputDir');
+
+        // after trends
+        const outputDir = this.options.outputDir;
+        if (!fs.existsSync(outputDir)) {
+            return;
+        }
+
+        const list = fs.readdirSync(outputDir);
+        if (!list.length) {
+            return;
+        }
+
+        Util.logInfo('clean output dir ...');
+        for (const item of list) {
+
+            // console.log('remove', item);
+            try {
+                Util.rmSync(path.resolve(outputDir, item));
+            } catch (e) {
+                // console.log('=======================', e);
+            }
+
+        }
+
     }
 
     // ==========================================================================
diff --git a/package.json b/package.json
index 66e82a6..2ce26f7 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
         "koa": "^2.15.3",
         "koa-static-resolver": "^1.0.6",
         "lz-utils": "^2.1.0",
-        "monocart-coverage-reports": "^2.11.1",
+        "monocart-coverage-reports": "^2.11.2",
         "monocart-locator": "^1.0.2",
         "nodemailer": "^6.9.16"
     },
diff --git a/tests/playwright.config.js b/tests/playwright.config.js
index c40a2f3..f66fd8c 100644
--- a/tests/playwright.config.js
+++ b/tests/playwright.config.js
@@ -186,6 +186,18 @@ module.exports = {
 
             trend: () => {
                 return new Promise((resolve) => {
+
+                    // const fs = require('node:fs');
+                    // fs.readFile('./.temp/monocart/index.json', (error, data) => {
+                    //     if (error) {
+                    //         console.log(error);
+                    //         resolve();
+                    //         return;
+                    //     }
+                    //     const json = JSON.parse(data);
+                    //     resolve(json);
+                    // });
+
                     const axios = require('axios');
                     axios.get('https://cenfun.github.io/monocart-reporter/index.json').then((res) => {
                         const json = res.data;