PurposeThis paper aims to study the effect of different rare earth oxide on the tribological properties of polyimide (PI) nanocomposites based on the CNT and GO reinforcements.Design/methodology/approachThe PI nanocomposites filled with different rare earth oxide based on the carbon nanotubes and graphene oxide were designed and prepared by hot press sintering. The mechanical and tribological properties of PI nanocomposites were carried out, and their reinforcement mechanisms were discovered.FindingsRare earth oxide had a weak influence on the impact strength of PI nanocomposites. Filling La2O3 can dramatically reduce the friction coefficient and wear rate of PI nanocomposites.Originality/valueThe PI nanocomposites filled with rare earth oxide based on the CNT and GO reinforcements were designed, and their mechanical and tribological properties were studied.