Abstract: The deep-sea robot is very useful in deep sea engineering. Based on a comparison and analysis of current deep-sea robots, this paper proposes a novel concept for a deep-sea walking-swimming robot, the purpose of which is to swim extensively in the sea and walk stably on the seafloor. The overall proposal, specifications and characteristics of the deep-sea walking-swimming robot are introduced. After an analysis of its environment and function characteristics, such key techniques as the regulation of the robot's walking/swimming attitude, cooperative current anti-turbulence of multi-legs and multi-joints, path planning for low energy consumption, dynamic seal of deep-sea joints and integration and optimization of the overall design are presented, showing that it is quite different from traditional underwater and multi-foot robots. Finally, the research progress of the above-mentioned techniques is also presented.