Based on the statistical method of flow factor,a mixed fluid lubrication model of oil seal lip was established.The energy conservation equation and viscoustemperature equation of oil seal were coupled.The temperature distribution of oil seal lip,the maximum temperature and temperature difference of oil seal lip under different rotational speeds were obtained by iterative solution.The sealing performances of oil seal with and without considering the temperature difference were compared and analyzed.The results show that with the increase of rotational speed,the maximum lip temperature is increased linearly,while the lip temperature difference is increased first and then decreased.When oil seal works,the temperature in the lip area is increased rapidly first and then decreased,and the closer it is to the lip tip,the higher the temperature is.Compared with the case without considering temperature,when considering the influence of temperature change,the thickness of oil film in the sealing area is decreased and the lubrication state is deteriorated,and the bearing capacity of oil film is decreased,which is not conducive to sealing.