Abstract: With the fast pace of ocean exploitation, unmanned underwater vehicles，as the most important means of ocean exploration for human, gained unprecedented attention and development. In this article, the definition and classification of the unmanned underwater vehicles are given. The current status and developing tendency of unmanned underwater vehicles in recent years are introduced, and the key technologies and future development direction of autonomous underwater vehicle are analyzed.

Key words:  unmanned underwater vehicle (UUV), autonomous underwater vehicle (AUV), autonomous system, motion control, communication and navigation, hunt and identify, efficient energy