Ferrofluids can meet the continuously improving stability requirements of lubricating oil film of sliding bearing under extreme working conditions due to its paramagnetic controllable rheological properties,and have a good application prospect in bearing lubrication.To explore the micro lubrication mechanism of ferrofluids,the microscopic model of ferrofluid lubrication on the interface of babbitt alloy was constructed and optimized by molecular dynamics simulation method,and the confined shear simulation was carried out according to the actual working conditions.The effects of temperature and shear rate on the lubrication behavior of PAO6-based ferrofluid on the interface of babbitt alloy were studied.Through the analysis of the relative concentration distribution,temperature distribution,velocity distribution,mean square displacement and interface adsorption energy during the sliding process,the mechanism of ferrofluid micro-lubrication was revealed from the molecular level.The results show that the PAO6-based ferrofluid has good stability and heat dissipation,and can adhere to the friction interface of babbitt alloy to play a good role in bearing and reducing wear.At high temperatures and high shear speeds,the magnetic liquid lubricating film still exhibits good stability,and the magnetic particles have good diffusion.The research results are helpful to improve the lubrication theory of nano-film and have practical significance for the engineering application of ferrofluids.