Lithium-ion power battery has become an important part of power battery. According to the performance and characteristics of lithiumion power battery, the influence of current common charge and discharge and different cooling methods on battery performance was analysed in this paper. According to the software simulation, in the 5C charge-discharge cycle, the maximum temperature of the cells with regular arrangement is 57.97°C, the maximum temperature of the cells with staggered arrangement is 55.83°C, and the maximum temperature of phase change cooling is 47.42°C. The most important thing is that the temperature difference between the cells with phase change cooling is only 5.5°C. Some simulation results of air cooling and phase change show that phase change cooling can control the heat dissipation and temperature rise of power battery well. The research in this paper can provide better theoretical guidance for the temperature rise, heat transfer and thermal management of automotive power battery.