In order to investigate the effect of molybdenum disulfide (2H-MoS2) on the thermo-oxidative aging and tribological properties of the composites of antioxidant 4020 and nitrile butadiene rubber (NBR),molecular dynamics (MD) simulations were used to establish the models of 4020/NBR and MoS2/4020/NBR composites,respectively.The effects of 2H-MoS2 on the thermo-oxidative aging properties,mechanical properties,and tribological properties of the composites at different temperatures were analyzed.The results show that the compatibility,stability and thermo-oxidative aging properties of the composites are effectively improved after adding MoS2,and the mechanical properties are also significantly improved.Even at a high temperature of 398 K,the composite can show excellent thermo-oxidative aging properties and mechanical properties.Compared with 4020/NBR composite,the friction coefficients of MoS2/4020/NBR composite at 298 K and 398 K are reduced by about 30% and 25%,respectively,and the wear rates are reduced by 5% and 7%,respectively,which indicates that MoS2 can effectively improve the tribological properties of NBR composites.