Triethanolamine functionalized reduced graphene oxide (rGO‐TEA(s)) nanocomposites have been synthesized by the hydrothermal method. The physical and chemical properties of rGO‐TEA(s) with different degrees of functionalization were characterized by transmission electron microscopy, X‐ray powder diffraction, Raman spectroscopy, and X‐ray photon spectroscopy. The cold rolling lubrication of the rGO‐TEA(s) prepared as nano‐lubricant additives were investigated using a two‐high rolling mill. The microscopic topographies of rolled strips were measured and evaluated by several physical characterizations. The results showed that the increase of functionalization time was favored to the reaction of triethanolamine and C–O–C groups on the GO surface, whereas the defects and disorder in graphene structure were repaired according to the intensity ratio of the D band to G band from 1.154 to 1.130. The cold rolling experiment results demonstrated that rGO‐TEA(s) exhibited excellent lubrication properties, especially the rolled surface lubricated by rGO‐TEA‐10h presented few defects and minimum roughness value. The admirable lubrication performance of rGO‐TEA‐10h was attributed to the formation of absorption film and consecutive carbonaceous protective film.