In order to reveal the lubrication characteristics of high-speed ball bearings under the sub-ring lubrication mode and improve the lubrication efficiency of ball bearings, a three-dimensional geometric model of high-speed ball bearings was established. By using multiple reference frame and VOF model, the two-phase flow field and temperature field of inner and outer ring in the bearing under different conditions were investigated, and the correlation law of lubricating oil flow and heat transfer was obtained. At the same time, the definition of the penetration rate was given quantitatively for the lubrication efficiency of the outer ring. The lubrication efficiency of ball bearings under-race lubrication was evaluated from the aspects of rotation speed and penetration rate. The results showed that the oil and gas distribution and temperature distribution in the lubrication under the ring are not uniform, and there was an obvious correlation between the two; the increase of speed reduced the oil volume fraction in the bearing. The oil distribution was more uniform which was useful for reducing the temperature difference between the inner and outer rings.