The invention discloses a three-level 
boost inverter in power electronic field. In the invention, a 
branch circuit consisting of a first 
diode and a first 
capacitor is connected in parallel with a 
branch circuit consisting of a second 
capacitor and a second 
diode and then is connected in parallel with a second switching tube to form a 
switched capacitor network, a third switching tube is connected with a fourth switching tube, a fifth switching tube is connected with a sixth switching tube, a 
branch circuit consisting of the third switching tube and the fourth switching tube and a branch circuit consisting of the fifth switching tube and the sixth switching tube are connected in parallel to form a single-phase inverting bridge network, the 
switched capacitor network produces a multi-level 
voltage and transmits the multi-level 
voltage to the inverting bridge network, a knot is drawn from a connecting part of the third switching tube and the fourth switching tube and is connected with an output filtering 
inductor, the output filtering 
inductor is connected with one end of an output 
capacitor, both ends of the output capacitor are connected in parallel with a load, and the 
voltage at both ends of the output capacitor is an output voltage. The three-level 
boost inverter also realizes effective direct-
current voltage boost while realizing the conversion from the direct-
current voltage to the multi-level voltage, and has remarkable boost capacity and adjustable boost 
transformation ratio.