如何在javascript中将base64文件重构为pdf文件?

使用 fs.writeFileSync(file, data[, options]) :

const fs = require('fs');

// get your response somehow...
const response = {
  file: 'PHN0eWxlPnRlRrU3VRbUNDJyAvPjwvcD4K',
  mime_type: 'text/html',
  document_type: 'shippingLabel'
};
// LUT for MIME type to extension
const ext = {
  'text/html': 'html',
  // ...
}

// save to shippingLabel.html
fs.writeFileSync(`${response.document_type}.${ext[response.mime_type]}`, response.file, 'base64');