Abstract: Reliability and economic efficiency are factors that must be considered when planning a power generation system that includes wind turbines and solar panels. Based on the wind speed and solar irradiance data, and considering the three-state shutdown model of the wind turbine and the two-state shutdown model of the photovoltaic generator, a reliability model with a wind-solar complementary system is established. By applying the sequential Monte Carlo method, the power generation system reliability index under different wind/solar installed capacity and different wind/solar configuration ratios is calculated. The load power shortage obtained in the reliability assessment is quantified as the reliability cost, and the integrated cost function is established in combination with the inherent cost of the system. Economic evaluation of small power generation systems with wind and solar generating unit is carried out in consideration of environmental benefits and fuel economy savings. The result shows that the proposed method is effective and can provide a certain reference for the actual planning of the small power generation system with wind turbines and solar panels.