let list = [
  {
    id: "27",
    order_number: "21251",
    tel: 13911111,
    weight: "10kg"
  },
  {
    id: "245",
    order_number: "223",
    tel: 31,
    weight: "10kg"
  },
  {
    id: "123",
    order_number: "312312321",
    tel: 3213123,
    weight: "10kg"
  }
];
let new_list = list.map(function(obj) {
  return {
    id: obj.id,
    order_number: obj.order_number,
    weight: obj.weight
  }
});

console.log(list);
console.log(new_list)