In order to guarantee the reliable and economical operation of the standalone micro grid, the optimal power capacity configuration need to be carried in the power system planning. The power capacity of independent micro grid is not only affected by regional load but also by natural resources such as the wind and solar energy. In this paper, the characteristics of natural resource condition in different regions are analyzed. A multiple objective optimization model with the goal of minimizing the annual generation cost is established, considering the reliability of power supply and electricity environmental protection. Constraints of electric power and energy balance are taken into account. The linearization algorithm is applied to solve the optimization model. The output scenario of renewable energy is simulated by the generative adversarial networks (GAN), and reduced by the improved K-Medoids clustering algorithm. In order to analyze the characteristics of the natural resources, the index evaluation system is established, and the evaluation grade of natural resources in 32 provinces of China is obtained based on the fuzzy evaluation method. This paper compares the power capacity configuration of standalone microgrid in five typical regions with different natural resources, hoping to provide some reference for the planning of standalone microgrid system.