The invention discloses a power output device which comprises N power modules and two output ends, wherein the N power modules are sequentially connected in series through a switch, a first output end is connected with a first power module, and a second output end is connected with the Nth power module; through connecting and disconnecting the switch, the output power of the device is changed; each power module comprises a three-layer current transform chain; the current transform chain comprises three power units, three input electric reactors, a current-equalizing electric reactor, the three power units are connected in series, the input electric reactors are respectively correspondingly connected with each power unit, and the current-equalizing electric reactor is connected with the three power units which are connected in series. According to the invention, the number of the power units which are connected in series can be controlled through the switch, thereby avoiding that the output of various voltages is realized by using a plurality of corresponding power units which are connected in series, and reducing the land-occupied area of equipment and the investment on equipment.