In order to study the micro mechanism of synergistic enhancement of the tribological and mechanical properties of nylon 6(PA6) composites by carbon nanotube (CNT) and graphene nanosheets (GNS),the tensile process and tribological behavior of PA6 and its composites were simulated by molecular dynamics,and the effects of CNT and GNS on the mechanical and tribological properties of PA6 composites were analyzed.Tribological models consisting of Fe atoms and pure PA6 and PA6/CNT,PA6/GNS,PA6/GNS/CNT composites were established,and the models were geometrically optimized,annealed and dynamically balanced.Friction simulation was carried out by applying 0.2 GPa stress and 0.01 nm/ps velocity to Fe atoms.The results show that the friction coefficient of PA6/GNS/CNT composite is 0.252,which is the lowest among all materials.Compared to the other three materials,PA6/GNS/CNT composite material has the best shear resistance,and both the elastic modulus and shear modulus are improved.By comparing and analyzing the radial distribution function,friction interface temperature and total potential energy of the four materials,the synergistic reinforcement mechanism of CNT and GNS on the tribological and mechanical properties of PA6 composites was revealed.It is pointed out that the addition of CNT/GNS reduces the interaction between PA6 and Fe atomic friction pairs through van der Waals and electrostatic forces,and one-dimensional CNT and two-dimensional GNS form a 3D hybrid stacking system through π-π stacking hybridization,synergistically enhancing the tribological performance of PA6.