Finally, I solved it using the superagent method

var charset = require('superagent-charset');
var superagent = charset(require('superagent'));


function agent(req,res){
  superagent.post(url+req.path)
    .type('form')
    .send(req.body)
    .set('Accept', 'application/json')
    .charset('gbk')
    .end(function (err, sres) {
      var html = sres.text;
      res.send(html);
  });
}
app.post('/list',function(req,res,next){
  agent(req,res)
})

res.charset = 'gbk';
res.send('some thing');

To send data from the background to the front end, add

            response.setCharacterEncoding("GBK");
        然后再    PrintWriter writer=response.getWriter();