Abstract: Multi-level converters have the advantages of low switching stress, low du/dt, and good output harmonic performance, which are widely used in high voltage frequency conversion speed regulation, new energy power generation, power systems, and other medium and high voltage large-capacity power conversion occasions. The hybrid active neutral point clamped (HANPC) multilevel converter has a large zero sequence voltage solution error, which leads to the problems of frequent phase voltage level jumps and large voltage ripples of DC link upper and lower capacitors. Therefore, a multi-stage zero-sequence voltage approximation optimization control method is proposed in this article. This article first discusses the coupling effects of different switching states and phase currents on the capacitor voltage ripples at different positions, and gives the voltage equalization control method of the floating capacitor and DC-link midpoint capacitor; on this basis, the zero-sequence voltage solution problem is transformed into an optimization problem, while considering the constraints of the linear modulation range to avoid over-modulation and reduce phase voltage level jumps. Simulations and experiments show that the method proposed in this article is suitable for different loads and different modulation indexes, which can smooth the reference modulation voltage and reduce the voltage level jumps, further reducing the voltage fluctuation amplitudes of DC-link upper and lower capacitors. This provides a reference for its application in medium and high voltage occasions.