A power output device comprises a frame, four drive units mounted on the frame. The four drive units are arrayed along the length of the frame; each drive unit comprises a transmission chain component, two rotary arms, a hanging rope, a transmission component, a first drive chain and a holding and lifting component; the transmission chain component comprises two rolling cylinders and two circulating chains; one end of the hanging rope is connected to a connector between the two circulating chains, and the other end is connected to a counterweight in a hanging manner; the transmission component comprises a spindle, a transmission shaft and a driven shaft which are linked synchronously, and the spindle is synchronously linked to the two rotary arms; the first drive chain is used for linking a first drive sprocket to one rolling cylinder synchronously. The four drive units are arrayed along the length of the frame sequentially and are linked synchronously, and the projections of the rotary arms of the four drive units on the radial cross section of the spindle is in a shape of a Chinese character of 'mi'. The power output device is capable of reducing energy consumption of coal, oil, natural gas and the like and reducing environment pollution.