There are abundant mineral resources in the deep sea. It is very important for the research and exploitation of deep-sea resources in the later stage to use deep-sea underwater equipment for exploration and sampling. As the whole power source of deep-sea underwater equipment, the power supply system directly determines the stable operation and working performance of the equipment. In this paper, the power supply system of deep-sea underwater equipment powered by umbilical cable is introduced, and the optimal design and development of the power supply system with umbilical cables are prospected. Firstly, the scheme design of the power supply system of the equipment is introduced from two aspects of AC transmission with umbilical cable and DC transmission with umbilical cable. Then, the optimization design is studied from three aspects: power quality management, fault diagnosis and protection of power supply system, multi-physical coupling field modeling and simulation of umbilical cable. Combined with practical engineering cases, MATLAB/Simulink is used to simulate and analyze the power supply system. Finally, the future development of the power supply system of deep-sea underwater equipment is prospected.