Three-level diode-clamped bridge converter is a good solution for high voltage and high power applications. However, the problem of excessive voltage stress is common in the switching on and off process of three-level inverter switch transistor. In order to solve the above-mentioned problems, after analyzing the stress of three-level inverter switch tube, a switch tube drive protection circuit is proposed, and the three-level drive waveform is designed and optimized. Finally, the effectiveness of the proposed method is verified by experiments on a three-level inverter experimental platform.