With the development of power systems with new energy as the main body, the characteristics of distribution are obvious, and the amount of terminal equipment increases sharply. The scheduling and control of massive power loads are faced with problems such as high delay and insufficient computing efficiency, and so it is urgent to establish an efficient communication network to effectively improve the operating efficiency and reliability of the power system. There is a joint optimization problem of service cache and VM migration in an edge network resource management that is not considered in existing edge computing technology combined with a power system. Thus this paper proposes an edge resource allocation strategy based on task unload, service cache and VM migration models to improve system performance. As for the coupling problem of service caching and VM migration, the original problem is decoupled into two sub-problems to achieve better resource allocation. The simulation results further prove that the proposed strategy has better performance and lower task processing delay than other schemes.