Abstract: The nano-ZnO was dispersed into water-based rolling fluid by dispersant, extreme pressure agent, rust inhibitor. And the best recipe and the best working conditions were selected by orthogonal experiment. The results show that under the conditions of nano-ZnO 0.4% (mass fraction), heating 60 °C, stirring 10min, the tribological properties is of optimum. The tribology analysis and cold rolling experimental results further indicate that excellent lubrication properties can be obtained using the best formula rolling fluid. Nanoparticles lubrication mechanism was analyzed by strip surface morphology and elemental analysis. It is argued that due to the extreme pressure film formed through combination of nanoparticles with additives and the filled defects on the strip surface by the nanoparticles, the surface roughness is lowered and thus the surface quality is improved.