High-speed machining requires higher speed and sufficient dynamic stiffness. To meet the requirement of sufficient dynamic stiffness, magnetic bearings are more complicated to implement. Although ball bearings have high dynamic stiffness, their critical speed is low. Therefore, a magnetic-spherical double-supported rotor system is proposed to meet the requirements of high-speed machining. Based on the Timoshenko beam theory, the finite element method is used to establish the dynamic model of the double-supported rotor system, and the accuracy of the model is verified experimentally. Based on this dynamic model, the inherent characteristics and vibration characteristics of the rotor system were analyzed through numerical simulation, the influence of the stiffness of ball bearings and magnetic bearings on the inherent characteristics was explored, and the vibration response amplitude of the rotor system with and without magnetic force intervention was compared. The vibration resistance of the double-supported rotor system is analyzed based on factors such as the system""s rotational speed, the size and position of the unbalanced mass.The results show that in a double-support rotor system, the magnetic force intervention of the magnetic bearing will significantly increase the critical speed of the rotor and reduce the vibration response amplitude of the system. The system vibration amplitude is proportional to the system speed and the size of the unbalanced mass, and the vibration is prone to occur at the rotor output end.