A multi-level inverter includes two N-level inverter units with pulse width modulation waves staggered by a phase of 180 degrees, and N is an integer greater than or equal to 3; a direct current power source module, where an output end thereof is connected to input ends of the two N-level inverter units; a transformer, where the transformer includes a primary side and a secondary side, an inductor of the primary side and an inductor of the secondary side are coupled, and one end of the inductor of the primary side and one end of the inductor of the secondary side are connected to output ends of the two N-level inverter units respectively. The two N-level inverter units are reversely coupled, and the other end of the inductor of the primary side and the other end of the inductor of the secondary side are connected.