<p>High speeds make it difficult for lubricant oil to remain on the contact area of angular contact ball bearings, resulting in starved lubrication. As a result, a new type of cage with diversion holes was developed to improve the effectiveness of oil–air lubrication in angular contact ball bearings at high speeds. Using the VOF model and MRF kinematic reference system, a model was established for oil–air two-phase flow inside bearing chamber. A comparative analysis was conducted for oil distribution, oil fluidity, and airflow field inside bearing chambers with diversion hole cage and conventional cage. Mechanism of lubricant oil entering diversion hole was explored. The results indicated that the diversion hole cage could change the volume fraction of oil phase inside bearing chamber, increase oil volume fraction phase in key lubrication area, and then improve lubrication efficiency. Meanwhile, the diversion hole cage can weaken influence of air curtain effect and increase mass flow rate of oil–air inlet. The migration of lubrication oil on the diversion hole cage includes three main stages, and large diameter of diversion hole cage helps lubrication oil enter into and pass through. This study proposes a novel way for increasing the lubrication effectiveness of bearings.</p>