Abstract: The 21 century is a period for human beings to explore oceans.Autonomous underwater vehicles and underwater robots expect an expansive applied future and are of great potential value.A new type of underwater turbine has been paid more and more attention for its high efficiency,maneuverability and low noise.This paper introduces the classification and the characteristics of new type underwater turbine imitating fish-fin,also introduces the research achievements and current state home and abroad,and forecasts the developing tendency.