Abstract: This paper proposes a modulation wave distribution method based on the power balance control of the quasi-Z-source cascaded inverter. The reactive power required by the system is provided by a certain cascaded unit,and the grid-connected active power is equally distributed by all cascaded units;According to this power allocation principle,all levels of connected units are generated.Unit modulation wave. At the same time,the constraint conditions of the pass-through duty cycle of the quasi-Z-source cascaded inverter to achieve power balance control are derived. Finally,through the carrier phase shift modulation to control the inversion of the connected units at all levels to achieve grid connection.Simulation and experiment results verify that this strategy can effectively guarantee the stability of the DC bus voltage and the maximum power output of the photovoltaic cell module when the input power of the cascade unit is unbalanced,and achieve unity power factor grid connection.