我是个比较喜欢用storyboard和xib的人。我个人的习惯就是，能用storyboard的一定不用代码手工撸。当然自己业余个人写的项目，基本上一个storyboard就搞定了。但涉及到多人合作下时候，一个storyboard还是挺蛋疼的，冲突难解决，打开storyboard极容易出现修改。结构大的时候打开还卡（也可能是我电脑太屌丝啦。。。）

下面介绍下我使用多个storyboard的习惯，仅供参看，不一定是最好的方案。

一、storyboard结构

1. 默认的Main.storyboard下我只有一个UITabBarController，如果你建立的是TabItem的模板项目，这个应该是默认的。注意，没有tabItem。
2. 给对应的每个TabBarItem建立对应的storyboard，比如我建立的MyTabItemOne.storyboard和MyTabItemTwo.storyboard。
3. MyTabItemOne.storyboard下我放的是一个UINavigationController作为初始Controller。
4. MyTabItemTwo.storyboard类似

二、代码层面

自定义UITabBarController和UINavigationController。将Main.storyboard下的UITabBarController改为自定义的SPTabBarController.swift。将MyTabItemOne（Two）.storyboard下的UINavigationController改为自定义的SPNavigationController.swift

SPTabBarController.swift

//
// SPTabBarController.swift
// SampleProject
//
// Created by LiuYanghui on 2016/11/14.
// Copyright © 2016年 LiuYanghui. All rights reserved.
//

import UIKit

class SPTabBarController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        // 添加所有子控制器
        addChildViewControllers()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - private method

    /// 添加所有子控制器
    private func addChildViewControllers() {
        setChildrenController(title: "One",image: UIImage(),selectedImage: UIImage(),storyboard: UIStoryboard(name: "MyTabItemOne",bundle: nil))

        setChildrenController(title: "Two",storyboard: UIStoryboard(name: "MyTabItemTwo",bundle: nil))

    }

    /// 添加一个子控制器
    private func setChildrenController(title:String,image:UIImage,selectedImage:UIImage,storyboard:UIStoryboard) {
        let controller = storyboard.instantiateInitialViewController()!
        controller.tabBarItem.title = title
        controller.tabBarItem.image = image
        controller.tabBarItem.selectedImage = selectedImage
        addChildViewController(controller)
    }
}

SPNavigationController.swift

//
// SPNavigationController.swift
// SampleProject
//
// Created by LiuYanghui on 2016/11/14.
// Copyright © 2016年 LiuYanghui. All rights reserved.
//

import UIKit

class SPNavigationController: UINavigationController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.interactivePopGestureRecognizer?.delegate = nil
    }

    override func pushViewController(_ viewController: UIViewController,animated: Bool) {
        if viewControllers.count > 0 {
            //隐藏tabbar
            viewController.hidesBottomBarWhenPushed = true

            viewController.navigationItem.leftBarButtonItem = setBackBarButtonItem()
        }
        super.pushViewController(viewController,animated: animated)
    }

    func back(){
        self.popViewController(animated: true)
    }

    // MARK: - Private method
    private func setBackBarButtonItem() -> UIBarButtonItem{
        let button = UIButton(type: .custom)
        button.setImage(UIImage(named: "navigationButtonReturn"),for: .normal)
        button.setImage(UIImage(named: "navigationButtonReturnClick"),for: .highlighted)
        button.setTitle("返回",for: .normal)
        button.setTitleColor(UIColor(red: 81/255,green: 81/255,blue: 81/255,alpha: 1),for: .normal)
        button.addTarget(self,action: #selector(SPNavigationController.back),for: .touchUpInside)
        button.frame.size = CGSize(width: 100,height: 30)
        // button 里的内容左对齐
        button.contentHorizontalAlignment = .left
        button.contentEdgeInsets = UIEdgeInsets(top: 0,left: -10,bottom: 0,right: 0)

        return UIBarButtonItem(customView: button)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

Xcode工程

Sample Project Github