The gearbox inputs power through the front vertical box of the machine or the tractor increases the rotational speed, and transmits the power to the crushing cutter shaft through the transmission shaft and belt. Through double-sided output, the machine's operating width can reach 3.5 meters to 6.5 meters. At the same time, it can also realize the secondary crushing function to achieve a better crushing effect on crops. The machine crushes the crop straw and then recycles packs, and reuses it, or directly returns it to the feed standard, or directly returns it to the field to rot to increase the fertility of the land. This type of gearbox will be used in the crushing devices of various equipment such as small square balers, dust-removing small square balers, round balers, straw return machines, etc.