In this paper, the model of wave motion at the abruptly changed section of rotating thin ring with rectangular holes was built up, and wave transmission and reflection were analyzed. Combined with closure phase principle, the vibration characteristic equation was derived. Then, natural frequency, mode shape and bifurcation of frequency were given. Natural frequencies of static ring derived by wave propagation method are compared with the results of finite element analysis, which validates the wave propagation approach, and it provides a theoretical basis for dynamic calculation of bearing solid cage by wave propagation approach.