With the increasing load traffic of base stations, the power supply cost of base stations has become the focus of operators. Low-cost and clean renewable energy such as solar energy is considered as an effective way to solve the power supply of base stations in the future. In order to meet the demand of green base station, a power supply framework with renewable energy as the main power supply and traditional power grid as the auxiliary power supply is proposed. Firstly, the Solar-Battery-Grid hybrid power supply system is designed to meet the power supply needs under different climate conditions. On this basis, the power and cost model of Solar-Battery-Grid hybrid power supply system is established. Then, the improved genetic algorithm is proposed to design the optimal configuration of the hybrid power supply system. Its purpose is to minimize the total cost of the base station. Finally, the simulation results showcase the feasibility of the hybrid power supply system. The effectiveness of the hybrid power supply system is proved by comparing with the traditional grid power supply system. In addition, the superiority of the improved genetic algorithm is verified by comparing with the benchmark algorithm.