Aiming at the neutral-point potential fluctuation inherent in the neutral-point clamped three-level inverter, a first-order model is established for the neutral-point voltage, and a neutral voltage balance strategy based on the fractional-order active disturbance rejection control is proposed. The balance strategy can estimate the compensation neutral-point potential disturbance in time on the basis of simplified parameter tuning. The simulation and comparison experiment results validate that the anti-interference ability and compensation speed of the fractional active disturbance rejection control are better than the traditional active disturbance rejection controller and the classic PI controller.