Abstract: Since the emergence in 2004, a great deal of enthusiasm has been dedicated to the research of graphene all over the world, and graphene is even named as "the material that changes the 21st century". The research progress in the tribology of graphene and its nanocomposite as lubricating additives is reviewed; and the monomer structure and surface modification of graphene as well as the composition and lubricating mechanism of graphene-based nanocomposite are summarized. It is pointed out that, as one of the hotspots in the field of material science and tribology, graphene nanoparticle has good tribological properties and its industrialization could give rise to enormous social and economic benefits; and graphene as a lubricating additive has promising prospect of application, thanks to its ultra-thin nanosheet structure, excellent mechanical properties and outstanding self-lubricating ability. However, graphene and its nanocomposite as lubricating nano-additives still face problems such as poor dispersion stability of graphene, unclear real-time service state in the friction process, etc; and the realization of the preparation of nanoscale graphene and its composite by green and environmentally acceptable routes as well as their application could help to promote energy conservation and emission reduction, thereby promoting the achievement of the "carbon peaking and carbon neutralization goals" and the development of our country’s advanced manufacturing industry at a high level.

Key words: graphene, nanocomposites, lubricating additive, tribology