Abstract: With the deepening advancement of China's electric power system reform, accelerating the construction of a national unified electricity market system has become a hot issue in recent years. The national unified electricity market system takes the national unified electricity spot market system as its core, and the structural design of the market system is a meticulous expression of its macro-architecture, which is also the top priority of the top-level design of the market system. This paper clarifies the connotation of the unified electricity spot market system and the extension of the four aspects of the structure including time, space, subject and object. On this basis, combined with the performance evaluation of the electric power spot market, the theory and method of spatial structure design, time structure and object structure collaborative refinement design and main structure design of the unified electric power spot market system are studied and proposed. An empirical analysis is carried out for the structure design of the unified electricity spot market system in Europe to verify the feasibility and effectiveness of the theoretical methods.