According to the energy conservation equation of oil seal and the viscosity-temperature equation,the temperature distribution of oil seal lip region under different operating conditions was obtained by iterative solution.Based on orthogonal experimental design and response surface fitting,the limit state function of oil seal operating conditions was obtained with the maximum temperature value and the temperature difference value.The reliability and reliability sensitivity of oil seal were analyzed according to limit state function of the parameters such as rotational speed,oil pressure,friction coefficient,roughness.The results show that the maximum temperature is the best index to study and analyze the influence of temperature on oil seal reliability.The friction coefficient has the highest sensitivity to the maximum temperature.Within the scope of study,an increase in the average roughness will increase the reliability of the oil seal,while an increase in the average rotation speed,oil pressure,and friction coefficient will reduce the reliability of the oil seal.As the variance of rotational speed,oil pressure,friction coefficient,and roughness increases,the reliability of the oil seal decreases.