Independent microgrids have important implications for solving the problem of electricity consumption and electricity consumption in distant islands or hills. This paper takes island micro-grid as the research object, and constructs an independent microgrid with distributed generation, for instance photovoltaic/solar heat/wind/diesel/storage. The goal is to decrease overall investment fee and the probability of insufficient electric supply, a dual-objective capacity optimization configuration model of the microgrid is established. NSGA-II algorithm is to deal with the established model, The best solution of each distributed power type and capacity in isolated islanded microgrid is obtained. The simulation results show that the optimal configuration scheme can ensure that the established microgrid has good economic benefits while ensuring the reliability of power supply.