The combine is a machine that simultaneously harvests, threshes, separates and cleans the grain, and finally gets the clean grain. It is generally composed of a harvesting platform, threshing system (including threshing, separation, grain cleaning device), conveying, rotating, walking device, grain compartment and control mechanism. The use of combine harvesters can greatly improve labor productivity and reduce labor intensity. According to the different power configuration, it can be divided into traction type, self-propelled type and suspension type.