//自己研究出来了。。。
//看着用吧
var Picture_Window_TitleCommand_prototype_makeCommandList = Window_TitleCommand.prototype.makeCommandList

Picture_Scene_Title_prototype_createCommandWindow = Scene_Title.prototype.createCommandWindow

Window_TitleCommand.prototype.makeCommandList = function() {
    Picture_Window_TitleCommand_prototype_makeCommandList.call(this);
        this.addCommand('你想要的名字', 'picture',true);
};

Scene_Title.prototype.createCommandWindow = function() {
    Picture_Scene_Title_prototype_createCommandWindow.call(this);
        this._commandWindow.setHandler('picture',  this.commandPicture.bind(this));
   
};

Scene_Title.prototype.commandPicture = function() {
    SceneManager.goto(Scene_Picture);
   
};

function Scene_Picture() {
    this.initialize.apply(this, arguments);
}

Scene_Picture.prototype = Object.create(Scene_Base.prototype);
Scene_Picture.prototype.constructor = Scene_Picture;

Scene_Picture.prototype.initialize = function() {
    Scene_Base.prototype.initialize.call(this);
};

Scene_Picture.prototype.create = function() {
    Scene_Base.prototype.create.call(this);
   
    this.createBackground();
};

Scene_Picture.prototype.start = function() {
    Scene_Base.prototype.start.call(this);
    this.startFadeIn(this.slowFadeSpeed(), false);
};

Scene_Picture.prototype.update = function() {
    if (this.isActive() && !this.isBusy() && this.isTriggered()) {
        this.gotoTitle();
    }
    Scene_Base.prototype.update.call(this);
};

Scene_Picture.prototype.stop = function() {
    Scene_Base.prototype.stop.call(this);
    this.fadeOutAll();
};

Scene_Picture.prototype.terminate = function() {
    Scene_Base.prototype.terminate.call(this);
    AudioManager.stopAll();
};

Scene_Picture.prototype.createBackground = function() {
    this._backSprite = new Sprite();
    this._backSprite.bitmap = ImageManager.loadPicture('文件名，文件放pictures文件夹里');
    this.addChild(this._backSprite);
};

Scene_Picture.prototype.isTriggered = function() {
    return Input.isTriggered('ok') || TouchInput.isTriggered();
};

Scene_Picture.prototype.gotoTitle = function() {
    SceneManager.goto(Scene_Title);
};

Drill大佬的插件合集里有“全自定义标题界面”

this._commandWindow.close();
$gameScreen.showPicture(1,"0_003",0,0,0,0,100,100,255,0);
不行