The magnetic levitation system is composed of four parts: a rotor, a sensor, a controller and an actuator. The actuator includes an electromagnet and a power amplifier. Assume that at the reference position, the rotor is subject to a downward disturbance and will deviate from its reference position. At this time, the sensor detects the displacement of the rotor from the reference point. The microprocessor as the controller converts the detected displacement into a control signal, and then The power amplifier converts this control signal into a control current, which generates magnetic force in the actuating magnet, thereby driving the rotor back to its original equilibrium position. Therefore, no matter whether the rotor is disturbed downward or upward, the rotor can always be in a stable equilibrium state.