Abstract: Practical researches showed that lubrication oil slick produced a great effect on bearing gluing,scuffing and contact fatigue.But,all the previous bearing simulations neglected its existence,causing obvious errors.In this paper,a new simulation method was proposed by assuming that bearing rings are rigid firstly.Based on Hertz contact theory,mechanical ball bearing model under radical and axial feed was set up with quasi-dynamics.Using Newton-Raphson method as a key calculation tool when solving the model,contact load and deformation were obtained,contact stiffness between each ball and inner ring,or each ball and outer ring were calculated.Considering the effect of lubrication oil slick on bearing dynamic characteristic on the basis of elastohydrodynamic lubrication(EHL) theory,oil slick rigidity was obtained.A new concept of equivalent synthetic rigidity was presented and solved.In view of above mathematical computation,exact dynamic simulation on ball bearing was carried out using ADAMS software.