Abstract: The present invention provides a method for DC-bus capacitance minimization of hybrid clamped converter (HCC), which includes: obtaining the system parameters of the HCC during operation; determining the reference wave; determining the duty ratio of each switch according to the reference wave; determining the total neutral point current of the system; the fundamental component of the upper and lower DC-bus capacitor voltage of the system; determining the maximum voltage fluctuation of the upper and lower DC-bus capacitors; determining the minimum DC-bus capacitance value that satisfies the requirements of system capacitor voltage fluctuation by traversing the capacitance value. The present invention not only reduces the design complexity and cost of the high-power HCC system, but also improves the power density and reliability of the converter.