Abstract: The lubrication and cooling conditions of high-speed roller bearings are greatly affected by the flow and spread characteristics of oil film on the surface of rotating parts (e.g. inner ring and associated cages) and the disintegration characteristics of ligaments and fragments in aircraft power plant. Based on the calculation results of the steady flow of oil film on the surface of a rotating disk, which was a topological geometry of rotating part with roller bearing, a model to calculate the critical transition characteristics of which the film disintegrated into ligaments and fragments was proposed using force equilibrium and liquid film instability theory. Subsequently, the steady flow characteristics of film were presented, and effects of the oil flow rate and the physical properties of oil on the critical transition characteristics of disintegration were discussed in detail. The calculation results show preliminarily that the film thickness decreased gradually at the radial direction, and due to slip between film and disk surface film velocity also decreased at the radial direction. The critical wave number and radius increased and the critical thickness decreased with increasing shaft speed. The critical radius of film disintegration increased with increasing oil flow rate and density, with decreasing the oil viscosity and surface tension coefficient. However, the critical thickness decreased with increasing oil density, and with increasing oil flow rate and viscosity. The critical thickness was shown to be influenced insignificantly by oil surface tension coefficient. The model proposed in the present work was validated by compared with the relevant experimental data.