Abstract: For unbalance vibration control of rigid rotor systems on magnetically levitated high-speed motors in the full rotational speed range, a vibration suppression method based on disturbance observers（DO） and polarity switching tracking filters（PSTF） was proposed. To identify synchronous vibration, the positive polarity tracking filter and the negative one are adopted before and after the rigid-model resonance speed range, respectively. Although the PSTF reduced the rotor vibration when the rotor rotated before and after the rigid-model resonance speed range by using the PSTF, vibration increased evidently and even destabilized the system during the rigid-model resonance speed range. Therefore, this vibration in the rigid-model resonance speed range was considered as a kind of disturbances, then the disturbance observer was adopted to observe this vibration and the method based on the PSTF realized the vibration suppression over the full rotational speed range. Finally, simulation and experiment results demonstrate the method based on the DO and the PSTF can effectively suppress the synchronous vibration over the full rotational speed range in different operation conditions.