The large impeller compost turning machine adopts a middle chain transmission mechanism to drive two large-diameter turning roulettes, symmetric turning, no dead angle adjustable speed shifting trolley, left and right displacement, low energy consumption to complete the large span turning work. In the case of deep stacking materials, the energy-saving transmission mechanism uses less power to complete the high-depth, large-span compost turning operation. Its hydraulic lifting system can automatically lift the turning plate to ensure that the equipment can move without obstacles. In addition, the supporting fully automated electrical control system further ensures that the equipment is easy to operate, safe and reliable. The large impeller compost turning machine can be customized with different spans according to the width of the fermentation trough. The width and height of organic fertilizer fermentation trough shall be determined according to the requirements of turning equipment.