Graphene flakes (G) and trihexyltetradecylphosphine bis (2,4,4-trimethylpentyl) hypophosphite ionic liquid (L) are mixed with engine oil (EO) containing zinc dialkyl dithiophosphate (ZDDP) additive to prepare different lubricants. Compared to EO and EO + G lubricant, EO + G+L lubricant provides improved friction, wear and anti-scuffing performance. The ionic liquid has a competitive adsorption relationship with graphene and ZDDP. The worn surface generates phosphates with shorter chain lengths and less ZDDP tribofilm. The ionic liquid also reduces the the presence of graphene in the tribofilm. The self-lubricating property of graphene and the tribofilm generated by the ionic liquid help to reduce the surface plastic deformation. The protective effects of ionic liquid and graphene inhibit the rapid consumption of the lubrication film.