In the new power system with renewable energy as the main body, the electric energy storage system will face the urgent demand of more frequent energy interaction and larger capacities. The structural design model of axial gap optimized superconducting magnetic energy storage is established, and the concept design scheme of large-scale superconducting energy storage is formed. Compared with the traditional solenoidal magnet, the energy storage of the optimized magnet is improved by 30%, and the investment cost of unit energy storage is effectively reduced. Considering that the new energy applications demand of 330 times of energy storage charge and discharge per day, the equivalent battery storage capacity of 10.8 GJ/3 MWh scalable superconducting energy storage system reaches 495 MWh, and the total cost of superconducting energy storage will be lower than that of battery energy storage after 10 years of full-load operation. Therefore, the proposed superconducting energy storage system is expected to achieve lower energy storage capacity in the renewable energy based power system with frequent energy interaction demands.