Abstract: With the development of camera technology, high-speed cameras have greatly contributed to capturing the movement and posture of animals, which has dramatically promoted experimental biology research. At the same time, with the concept of bionics gradually gaining popularity among researchers, the design of robots is absorbing more and more biological features, where the interest in the bio-inspired robot is hewed out. Compared with the traditional robot, the bio-inspired robot imitates the motion pattern to achieve similar propulsion features, which may be more effective and reasonable. In this paper, the motion patterns of aquatic animals are divided into four categories according to their propulsion mechanisms: drag-based, lift-based, jet-based, and interface-based. And bio-inspired robots imitating aquatic prototypes are introduced and reviewed. Finally, the prospect of aquatic bio-inspired robots is discussed.

Key words: Bionic , · Bio-inspired robot , · Aquatic animal , · Propelling mechanism , · Structure design