Herein, copper perrhenate (Cu(ReO4)2) was synthesized using a micro-emulsion method and adhered tographene (Gr) using an ultrasonic process. Then, the as-prepared Cu(ReO4)2/Gr composite was added intothe synthetic oil as a lubricant additive with the help of ionic liquid to achieve enhanced dispersionstability within the base oil. The tribological performances of the Cu(ReO4)2/Gr additive wereinvestigated using four-ball tests and the ball-on-disk reciprocating configuration under varioustemperatures. The potential lubrication mechanisms of the Cu(ReO4)2/Gr additive were performed usinga series of characterization methods including XRD, Raman, SEM-EDS, TEM, DSC/TG, and XPS. The resultsof four-ball tests at room temperature indicated that the Cu(ReO4)2/Gr additive could substantiallyimprove the tribological performances of the base oil. The smallest coefficient of friction (COF) and wearscar diameter (WSD) values were 0.068 and 495 mm, respectively, when 0.05 wt% of Cu(ReO4)2/Gr wasadded. Additionally, the graphene accelerated friction-induced heat transfer, which led to decreasedfriction and wear. The results of reciprocating friction experiments at elevated temperatures revealedthat the Cu(ReO4)2/Gr additive had excellent friction-reduction properties when the temperature washigh. This could be attributed to the generation of a protective layer containing tribo-oxides from thealloy, some residual carbides and copper perrhenate induced by friction heat and stress. This protectivelayer was uniformly and stably covered on the worn surface, which could effectively alleviate directcontact between the rubbing pair.