An improved nonlinear dynamic model of high-speed ball bearings with elastohydrodynamic lubrication is adopted to predict the movements of balls and power loss of ball bearings for defining the boundary conditions of a computational fluid dynamics (CFD) model. Then, this method of combining nonlinear dynamic and CFD models is validated through the experimental verification. Subsequently, oil–air flow and temperature distribution inside the bearing chamber are studied at low and high speeds and light and heavy loads. The effect of nozzle’s position on the formation of oil film and heat dissipation is revealed under combined loads. The research results provide a theoretical basis for engineering application of high-speed rolling bearings.