Abstract: The effects of nano Serpentine, nano La₂O₃ and environmental factors on the tribological properties of nano Serpentine-nano La₂O₃/polytetrafluoroethylene(PTFE) composites were investigated by orthogonal test. The self-made sand-dust environment simulation device was used to improve the existing MMU-5G friction and wear tester, and the tribological experiment was carried out using the test machine. The wear surface and transfer film morphology of the nano Serpentine-nano La₂O₃/PTFE composites were observed by SEM and the wear mechanism was analyzed. The results show that the friction coefficient of nano Serpentine-nano La₂O₃/PTFE composites is greatly influenced by the environmental factors and the friction coefficient of dry friction is lower than that in sand-dust environment. The nano Serpentine content has the greatest influence on the wear rate of nano Serpentine-nano La₂O₃/PTFE composites. When the nano Serpentine mass fraction is 9wt%, the wear rate of nano Serpentine-nano La₂O₃/PTFE composites is the lowest. The wear mechanism of dry friction is mainly adhesive wear, and the wear mechanism in sand-dust environment is mainly abrasive wear.