A multi-level inverter, wherein the multi-level inverter comprises a main topology, four switches, and a controller, and the main topology comprises a power supply, at least one flying capacitor, and at least four semiconductor switches; characterized in that the multi-level inverter comprises at least four resistors, wherein the at least four resistors comprise a first resistor, a second resistor, a third resistor, and a fourth resistor; the four switches are a first switch, a second switch, a third switch and a fourth switch; a first end of the flying capacitor is electrically connected to a positive electrode of the power supply through at least one of the semiconductor switches, a second end of the flying capacitor is electrically connected to a negative electrode of the power supply through at least an other one of the semiconductor switches, the controller is electrically connected to the switches, the controller is electrically connected to the main topology, the flying capacitor is connected in parallel to at least two semiconductor switches that are connected in series between the first end and the second end of the flying capacitor, at least one semiconductor switch is disposed on a first connection line between the first end of the flying capacitor and the positive electrode of the power supply, and at least one semiconductor switch is disposed on a first connection line between the second end of the flying capacitor and the negative electrode of the power supply; the first switch and the first resistor are connected in series between the first end of the flying capacitor and the positive electrode of the power supply; the fourth switch and fourth resistor are connected in series between the first end of the flying capacitor and the negative electrode of the power supply; the second switch and the second resistor are connected in series between the second end of the flying capacitor and the positive electrode of the power supply; the third switch and the third resistor are connected in series between the second end of the flying capacitor and the negative electrode of the power supply; and the controller is configured to: before the main topology works, control the switches to be simulateneously closed, and when detecting that charging the flying capacitor is completed, by detecting that the voltage of the flying capacitor has reached a pre-set value, control the switches to be simulateneously open. the multi-level inverter comprises at least four resistors, wherein the at least four resistors comprise a first resistor, a second resistor, a third resistor, and a fourth resistor; the four switches are a first switch, a second switch, a third switch and a fourth switch; a first end of the flying capacitor is electrically connected to a positive electrode of the power supply through at least one of the semiconductor switches, a second end of the flying capacitor is electrically connected to a negative electrode of the power supply through at least an other one of the semiconductor switches, the controller is electrically connected to the switches, the controller is electrically connected to the main topology, the flying capacitor is connected in parallel to at least two semiconductor switches that are connected in series between the first end and the second end of the flying capacitor, at least one semiconductor switch is disposed on a first connection line between the first end of the flying capacitor and the positive electrode of the power supply, and at least one semiconductor switch is disposed on a first connection line between the second end of the flying capacitor and the negative electrode of the power supply; the first switch and the first resistor are connected in series between the first end of the flying capacitor and the positive electrode of the power supply; the fourth switch and fourth resistor are connected in series between the first end of the flying capacitor and the negative electrode of the power supply; the second switch and the second resistor are connected in series between the second end of the flying capacitor and the positive electrode of the power supply; the third switch and the third resistor are connected in series between the second end of the flying capacitor and the negative electrode of the power supply; and the controller is configured to: before the main topology works, control the switches to be simulateneously closed, and when detecting that charging the flying capacitor is completed, by detecting that the voltage of the flying capacitor has reached a pre-set value, control the switches to be simulateneously open.