The processing quality of vertical machining workpiece is affected by the rotor’s axial vibration of high-speed motorized spindles. This paper presents a dynamic model by the finite element to discuss the dynamic behaviors of high-speed motorized spindles. It has been found that the axial rigid vibration is the first natural mode of vibration and the first natural frequency of axial vibration is lower than radial vibration. The good agreement between the theoretical results and the experimental data indicates that the model can describe the dynamic characteristics of the axial vibration. Finally, the axial vibration active suppression theory of high-speed motorized spindles has been carried out based on the linear quadratic optimal control theory. The simulation result shows that the axial vibration amplitude of closed-loop system will attenuate fast compared with the open-loop system.