When designing the power source configuration of fuel cell bus, only the power and fuel economy during the driving process were considered, and the impact of the other stages of the vehicle was ignored. In view of this situation, the energy consumption and emissions of fuel cell bus in all life cycle stages were analyzed based on the LCA (Life Cycle Assessment) theory, and a LCA model of fuel cell bus was established. By analyzing the life cycle energy consumption and emissions with Chinese urban bus driving cycle, the results showed that the power source configuration of fuel cell bus could be optimized. The optimal scheme of power source configuration was obtained by using genetic algorithm. The life cycle energy consumption and emissions of the fuel cell bus with optimal power source configuration were lower than those of the battery electric bus by, respectively, 24.86% and 25.76%, and were lower than those of the fuel cell bus with highpower fuel cell system by 12.11% and 6.51%, respectively.