thanks for = thank you for?也就是说如果想表达“感谢他的帮助”,不能使用Thanks for his help 这种句子吗

Thanks for his help 完全可以
因为我们常说 thanks for your help
不过把your换成his罢了

如果对第二人称说的话“thanks = thank you”，可以用Thanks for his help.

个人认为,使用“Thanks for his help.”完全可以.
一般说“Thank for his help.”
这是用“thank for sb.”这种动词短语的情况.
也可以直接说“I thank sb.(him/her/them等)”.这是动词“thank”之后直接跟宾语的情况.

要用 Thanks to his help