According to different work requirements and work scenes, there are many kinds of underwater robots. With the continuous improvement of various functions, more attention is paid to the reliability of underwater vehicles, especially the manned submersible (HOV). In order to improve the ability of underwater vehicles to complete various tasks more safely and efficiently, scholars from various countries have carried out research on the thruster which is most prone to failure, and put forward many thruster fault diagnosis and fault-tolerant control methods. This paper summarizes the fault diagnosis and fault-tolerant control methods of the thruster when the underwater vehicle is hovering at a fixed point, facing the requirements of high precision and stability, and hopes to enlighten the next research direction.