Graphene-based nano lubricant additives attract more and more attention because of their superior lubricating performance as well as green and ashless properties. Graphene-based nanocomposites exhibit excellent tribological performances due to the synergistic “slide-roll” effect. In this work, we developed a novel nanocomposite constructed by graphene materials (G) and CuO nanoparticles, named CuO@G, which has superior tribological properties to each component (pure CuO or pure graphene materials) and the mixture (Graphene + CuO) under different testing conditions due to the synergistic effect. By adding 0.5 wt% CuO@G to PAO-6 oil, the coefficient of friction (COF) is reduced by more than 50%, and the wear scar almost disappears. The study provides a novel and promising method for the synthesis of graphene-based lubrication nanomaterials, which has high potential for lubrication applications.