Disclosed is a three-level Boost converter neutral-point potential balance control method. The method is characterized by comprising the steps that 1, a voltage sensor VTincap1 is arranged on a three-level Boost converter output filter capacitor Cb1, detection data is capacitor voltage ucb1, a voltage sensor VTincap2 is arranged on the output filter capacitor Cb2, and the detection data is capacitor voltage ucb2; 2, a controller is connected to a three-level Boost converter, and the controller comprises an AD conditioning circuit, a DSP, an FPGA and a driving circuit; the two input ends of thecontroller are connected with the voltage sensor VTincap1 and the voltage sensor VTincap2 respectively, the sampling signal capacitor voltage ucb1 and the capacitor voltage ucb2 enter the controller,and output signals of the controller are drive pulse connected to two switching tubes Qb1 and Qb2; a deviation voltage gain feature coefficient sectional analytical expression is given, and the sectional fitting method based on maximum deviation voltage conditions is put forwards, so that different duty ratio section phase delay boundary conditions are determined, and therefore the deviation voltage is better and effectively regulated.