In order to adapt to various combat tasks in the increasingly complex marine environment, unmanned surface vehicles usually operate cooperatively in a group mode, among which unmanned surface vehicles formation control has developed rapidly in recent years. The present paper reviews the development of unmanned surface vehicle structures presently, and discusses the latest research of three key technologies, i.e., unmanned surface vehicles tasks assignment, formation control and obstacle avoidance. Finally, the research directions and future trends of unmanned vehicle formation control are summarized and prospected.