Lubrication characteristics can greatly affect the service performances of ball bearings. To further clarify the variation law of oil–air distribution in bearing cavity, a new simulation method combining the dynamic and computational fluid dynamics (CFD) models is presented. The relative motion between the ball and the cage caused by the cage clearance is obtained by the dynamic model. The coupling model uses the multi-reference frame (MRF) method and local remeshing approach (LRA) to describe the motion of each bearing component. The oil–air two-phase (OATP) flow is described through the volume of fluid (VOF) numerical model. Note that the lubricating oil content in the bearing cavity decreases significantly with the increment of rotation speed. There is a sudden change of pressure at the contact area between the ball and inner raceway. The relative motion of ball caused by the cage clearance has a certain effect on the local lubrication; however, it has little effect on the overall lubrication characteristics.