这句话的具体意思要看上下文.
可以是：我刚刚写完这本书 I have just finished （writing）the book
也可以是：我刚刚读完这本书I have just finished （reading）the book
还可以是：我刚刚校对完这本书I have just finished （proofreading）the book
我刚刚编辑完这本书I have just finished （editing）the book
我刚刚印刷完这本书I have just finished （printing）the book
我刚刚复印完这本书I have just finished （copying）the book
等等