首先我们来看下can't wait to do sth.和can't wait doing sth.的大致意思：
can't wait to do sth.：词性为短语，can't wait to do sth. 是一个固定搭配，表示非常期待做某事。
can't wait doing sth.：词性为短语，can't wait doing sth. 是一个固定搭配，表示非常期待做某事。
通过下面的表格我们了解下can't wait to do sth.和can't wait doing sth.的含义、发音和用法
接下来让我们看下can't wait to do sth.和can't wait doing sth.的用法区别：
1.语法结构：can't wait to do sth. 的主语是待完成的动作，而 can't wait doing sth. 的主语是待完成动作的对象。
例子：
-I can't wait to travel!
(我迫不及待地想去旅行！)
-I can't wait to read this book!
(我迫不及待地想看这本书！)
2.使用场景：can't wait to do sth. 更常用于表达对某个具体事件或行为的期待，而 can't wait doing sth. 更常用于表达对某个状态或情况的期待。
例子：
-I can't wait to see you!
(我迫不及待地想见到你！)
-I can't wait to get married!
(我迫不及待地想结婚！)
3.动作时态：can't wait to do sth. 表示对将来即将发生的动作的期待，而 can't wait doing sth. 表示对已经发生或正在进行的动作的期待。
例子：
-I can't wait to travel!
(我迫不及待地想去旅行！)
-I can't wait to see you!
(我迫不及待地想见到你！)
4.情感强度：can't wait to do sth. 强调的是情感强烈的迫切期待，而 can't wait doing sth. 强调的是对某种状态或情况的无法忍受。
例子：
-I can't wait to get married!
(我迫不及待地想结婚！)
-I can't wait to read this book!
(我迫不及待地想看这本书！)
迫不及待要去做某事了
wait to do something （等着要去做某事，既然是等了，事情肯定是还没开始做的。to do 可以表达要去做的意思，但是 doing 表达的是已经开始在做了的意思，跟“等”这个字玩不到一块啊）本回答被网友采纳