注意: 需要添加res.setEncoding(“binary”);

var http = require('http');
var fs = require('fs');
var url = ""; //-- 目标地址

var req = http.get(url,function (res)
{
  var fileData ="";
  res.setEncoding("binary");
  console.log("loading...");
  res.on("data",function (chunk) { fileData += chunk; });
  res.on("end",function () {
  //-- 本地文件路径
  fs.writeFile("D:/ttt/1/newFils", fileData, "binary", 
    function (err) {
      if (err) { return;console.log("failed to save"); }
      console.log("success to save");
    });
  });
  res.on("error",function (err) {
    console.log("failed to load");
  });
});

By Pury.