#### 難度：阿里p5 ~ p6 ~~~ const fs = require('fs'); const path = 'xxx/'+ Date.now() +'.png'; //去掉圖片base64碼前面部分data:image/png;base64 const base64 = data.replace(/^data:image\/\w+;base64,/, ""); //把base64碼轉成buffer對象， const dataBuffer = new Buffer(base64, 'base64'); fs.writeFile(path, dataBuffer, function(err){//用fs寫入文件 if(err){ console.log(err); }else{ console.log('寫入成功！'); } }) ~~~ 一般你要是做出來了將base64轉化成png文件，面試官又會壞壞的讓你舉一反三一下，會問你：實現一下將png文件，轉化成base64， ~~~ const fs = require("fs"); const util = require("util"); // 例：xxx/xx/xx.png const imageData = await util.promisify(fs.readFileSync(fileUrl)); const imageBase64 = imageData.toString("base64"); const imagePrefix = "data:image/png;base64,"; console.log(imagePrefix + imageBase64); ~~~ ## 摘自 [ 用nodejs，將base64轉化成png文件](https://juejin.im/post/5d46f433e51d4561ca2121fc#heading-15)