The auxiliary bearing is used to support the highspeed drop suspension rotor in the active magnetic suspension bearing system, and its impact resistance directly affects the safety and reliability of the magnetic suspension bearing system. In order to study the impact resistance of the auxiliary bearing in the vertical active magnetic suspension bearing system, the fullload hybrid ceramic ball bearing was used as the auxiliary bearing, the force analysis of the rotorauxiliary bearing system was carried out, and the dynamic model of the rotorauxiliary bearing was established. Multibody dynamics software was used to simulate the impact force on the auxiliary bearing during the rotor drop to the auxiliary bearing. The influence of the drop speed and the dynamic balance accuracy level on the impact force was analyzed under the eccentric state of the rotor. The results show that as the drop speed and dynamic balance accuracy level increase, the axial impact force on the auxiliary bearing remains unchanged, and the radial impact force increases.