Rubber O-rings are prone to aging and leakage under high temperature and pressure,and the maximum contact pressure and permanent compression deformation are not sufficient to determine the sealing performance of the sealing system.In order to study the effect of aging of rubber O-ring on sealing performance more precisely under high temperature and pressure,the leakage rate and performance data of rubber O-ring after aging were obtained through experiments,a finite element simulation model was constructed,and the contact pressure of sealing surface under different aging time was obtained.The theoretical leakage rate was calculated by combining the fluid-solid coupling model,and the sealing performance of the rubber O-ring was evaluated by comparing the experimental leakage rate and sealing surface contact pressure after different aging times.By comparing the results obtained from the numerical model with the experimental results,it is found that the theoretical model is in good agreement with the actual situation,which verifies that the theoretical model can provide guidance for the analysis and prediction of the aging behavior of rubber O-rings.