In view of the acidity and alkalinity of seawater in the actual operation of O-rings in marine equipment and the special marine environment,the accelerated aging life test for O-rings was carried out.A test bench for simulating the accelerated life of aging in the marine environment was designed based on the empirical formula of rubber aging and the Arrhenius acceleration model.The aging acceleration test at the temperatures of 35 ℃,50 ℃ and 65 ℃ was carried out under the environment of humidity of 80%,salinity of 35% and pH of 8.22.The aging kinetic model of nitrile rubber seal ring was established,and the variation law of compression set rate with time at different temperatures,as well as the function relationship between temperature and aging time and compression set rate,was studied.The service life of O-ring in offshore equipment was predicted.The results show that when the sealing ring ages in the same medium and different temperature media, there is no significant change in the decreasing rate of service life with the increasing of temperature.Using the established aging kinetic model of the sealing ring,it is speculated that the service life of the sealing ring in the seawater environment from 25 ℃ to 30 ℃ is between 1 and 1.5 years,which is basically consistent with the actual service life of the sealing ring.