npm install express multer multer --save

➜ upload-custom-filename git:(master) ✗ tree -L 1
.
├── app.js # 服务端代码，用来处理文件上传请求
├── form.html # 前端页面，用来上传文件

var fs = require('fs');
var express = require('express');
var multer = require('multer')

var app = express();
var upload = multer({ dest: 'upload/' });

// 单图上传
app.post('/upload', upload.single('logo'), function(req, res, next){
  res.send({ret_code: '0'});
});

app.get('/form', function(req, res, next){
  var form = fs.readFileSync('./form.html', {encoding: 'utf8'});
  res.send(form);
});

app.listen(3000);

<form action="/upload-single" method="post" enctype="multipart/form-data">
  <h2>单图上传</h2>
  <input type="file" name="logo">
  <input type="submit" value="提交">
</form>

var fs = require('fs');
var express = require('express');
var multer = require('multer')

var app = express();
var upload = multer({ dest: 'upload/' });

// 多图上传
app.post('/upload', upload.array('logo', 2), function(req, res, next){
  res.send({ret_code: '0'});
});

app.get('/form', function(req, res, next){
  var form = fs.readFileSync('./form.html', {encoding: 'utf8'});
  res.send(form);
});

app.listen(3000);

<form action="/upload-multi" method="post" enctype="multipart/form-data">
  <h2>多图上传</h2>
  <input type="file" name="logos">
  <input type="file" name="logos">
  <input type="submit" value="提交">
</form>

var fs = require('fs');
var express = require('express');
var multer = require('multer')

var app = express();
var upload = multer({ dest: 'upload/' });

// 单图上传
app.post('/upload', upload.single('logo'), function(req, res, next){
  var file = req.file;

  console.log('文件类型：%s', file.mimetype);
  console.log('原始文件名：%s', file.originalname);
  console.log('文件大小：%s', file.size);
  console.log('文件保存路径：%s', file.path);

  res.send({ret_code: '0'});
});

app.get('/form', function(req, res, next){
  var form = fs.readFileSync('./form.html', {encoding: 'utf8'});
  res.send(form);
});

app.listen(3000);

<form action="/upload" method="post" enctype="multipart/form-data">
  <h2>单图上传</h2>
  <input type="file" name="logo">
  <input type="submit" value="提交">
</form>

var upload = multer({ dest: 'upload/' });

var fs = require('fs');
var express = require('express');
var multer = require('multer')

var app = express();

var createFolder = function(folder){
  try{
    fs.accessSync(folder); 
  }catch(e){
    fs.mkdirSync(folder);
  } 
};

var uploadFolder = './upload/';

createFolder(uploadFolder);

// 通过 filename 属性定制
var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, uploadFolder);  // 保存的路径，备注：需要自己创建
  },
  filename: function (req, file, cb) {
    // 将保存文件名设置为 字段名 + 时间戳，比如 logo-1478521468943
    cb(null, file.fieldname + '-' + Date.now()); 
  }
});

// 通过 storage 选项来对 上传行为 进行定制化
var upload = multer({ storage: storage })

// 单图上传
app.post('/upload', upload.single('logo'), function(req, res, next){
  var file = req.file;
  res.send({ret_code: '0'});
});

app.get('/form', function(req, res, next){
  var form = fs.readFileSync('./form.html', {encoding: 'utf8'});
  res.send(form);
});

app.listen(3000);

<form action="/upload" method="post" enctype="multipart/form-data">
  <h2>单图上传</h2>
  <input type="file" name="logo">
  <input type="submit" value="提交">
</form>