struggle只能做不及物动词吗?

对，只能作不及物动词。在接名词时，得与介词连用。
比如：
He struggled to control his temper.
他努力控制住自己的脾气。
Several people were hurt in the struggle.
在打斗中，有几个人受伤。
He struggled with his assailants and eventually drove them off.
他同攻击他的人进行搏斗，最后把他们赶走了。

也可以作及物动词。