你改变的是trim,节点的宽高本身就不会变啊,你要是改变sizeMode才会改变节点的大小的
你加载的时候不要用cc.texture,用cc.spriteframe就可以了。然后动态改变sizeMode

代码:
cc.resources.load("weiba-1", cc.SpriteFrame, null, (err, sf: cc.SpriteFrame) => {
if (err) return console.error(err);
let child = new cc.Node();
child.setParent(cc.find("Canvas/2"));
child.active = true;
let spriteCom = child.addComponent(cc.Sprite);
spriteCom.trim = true;
spriteCom.sizeMode = cc.Sprite.SizeMode.TRIMMED;
spriteCom.spriteFrame = sf;
this.schedule(() => {
this.tip.string = '2:' + child.width + ',' + child.height;
spriteCom.sizeMode = spriteCom.sizeMode == cc.Sprite.SizeMode.TRIMMED ? cc.Sprite.SizeMode.RAW : cc.Sprite.SizeMode.TRIMMED;
}, 1, 100, 0)
})