Maglev wind turbine generator (MWTG) technology has been widely studied due to its low loss, low maintenance cost, and high reliability. However, the dynamics of the magnetic bearing system differ fromthe those of the traditional mechanical bearing system. A horizontal axial MWTG supported with a permanent magnetic bearing is designed in this research and the radial forces and the natural frequencies of the rotor system are studied. The results show that the generatorhas a cyclical magnetic forceand an unreasonable bearing stiffness may mean that the rotor system needs to work in the resonance region; the bearing stiffness is the key factor to avoid this problem. This is the main rule of the bearing stiffness design in the MWTG, and this rule can also be used in other maglev permanent magnet motors.