With the global trend of advocating environmental protection, energy conservation and emission reduction, and low-carbon travel, electric vehicles have been vigorously developed. As the power source of electric vehicle, power battery pack is one of the core components of electric vehicle. At present, the mainstream battery used in electric vehicles at home and abroad is lithium-ion battery, which has the advantages of high power density and energy density, low cost, long service life and no memory effect. But its performance is greatly affected by temperature. Therefore, it is imperative to carry out thermal management of electric vehicles. Firstly, the capacity, resistance and temperature rise of 18650 lithium-ion battery were tested by building a test platform; then, the consistency between the simulation results of single temperature rise and the experimental results was compared; finally, the power lithium-ion battery pack model was established, through single factor analysis and orthogonal experiment, the effects of filter plate free area ratio, battery spacing, wind speed and battery bottom distance on the battery were studied. The influence of maximum temperature and temperature difference were studied. When the battery was discharged at 1 C, it was concluded that adding filter plate improves the consistency of temperature field of battery pack, and the temperature difference of battery pack was the minimum when the free area ratio of filter plate was 0.1, 0.9 and 0.9. With the increase of wind speed, the maximum temperature decreased,temperature difference of battery pack first increased and then decreased. With the increase of battery spacing, the maximum temperature of battery pack first increased and then decreased, the temperature difference first increased, then decreased and increased at last.With the increase of the distance from the bottom of the battery, the maximum temperature of the battery pack first decreased and then increased. Finally, the best combination of 6 m/s, 4 mm and 4 mm was obtained by orthogonal experiment, which decreased 22.5% and 74.8% respectively compared with the maximum temperature and temperature duffurence before optimization.