可以参考下:
var sprite:Sprite = new Sprite();
sprite.graphics.drawRect(100,100,100,100,"#ff9900");
var hitarea:HitArea = new HitArea();
var graphics:Graphics = new Graphics();
graphics.drawRect(100,100,100,100,"#ff9900");
hitarea.hit = graphics;
sprite.hitArea = hitarea;
其中graphics可以是个不规则的区域,以此来实现你的需求!