A repulsive magnetic bearing supports a rotating shaft without contact by utilizing a magnetic repulsive force between the magnets. However, because of the nonlinear characteristic of the magnetic repulsive force, the vibration during passage through the critical speed may increase. This paper investigates a vibration suppression method of the rotating shaft supported by the repulsive magnetic bearing. A vibration suppression method by controlling the axial displacement of the repulsive magnetic bearing is proposed. Its axial displacement control generates the changes of both the linear and the nonlinear coefficients of stiffness. The influence of the parameters of the axial displacement control are investigated, and these results are validated experimentally.