The tribological performance and rolling lubrication properties of the BP/TiO 2 nanocomposites as water-based lubrication additives (BP/TiO 2 -WL) were investigated by the ball-on-disc tribometer and four-high rolling mill. The results indicated that the average coefficient of frictions (COFs) and wear rate of the 0.08 wt % BP/TiO 2 -WL were reduced by 24.5% and 59.5%, respectively, compared with ultrapure water. The lubrication mechanisms of the BP/TiO 2 -WL were dominated by the synergistic effect between the BP nanosheets and TiO 2 nanoparticles and the formation of tribological reaction films. In addition, due to the addition of the BP/TiO 2 composite nanofluids, the rolling force and surface roughness of the titanium alloy plate during the rolling process were decreased by 17.5% and 32.2%, respectively. Therefore, BP/TiO 2 nanocomposites as water-based lubrication additive have shown potential application in the field of titanium alloy plate cold rolling. • A new lubricant with excellent lubricating properties and environment-friendly for titanium alloy cold rolling were proposed. • The synergistic effect between BP nanosheets and TiO 2 nanoparticles can significantly enhance lubrication performance. • The application of BP/TiO 2 nanofluid can reduce the rolling force and surface roughness in cold rolling process. [ABSTRACT FROM AUTHOR]