According to the operating characteristics of the surface power supply system regarding to the process of deep-sea mining operations, the space layout, specification verification, structural design, etc. being analyzed, the deck power supply integrated module that meets the requirements of the classification platform ship specifications is designed, and the structural strength of the power supply module is standardized and optimized by the finite element analysis. A set of design methods suitable for offshore power supply system is sorted out, which provides a reference for the design of surface power supply system for the deep-sea mining.