The invention relates to the technical field of agricultural machinery, in particular to an automatic cutter sharpening and setting system of a silage harvester. The automatic cutter sharpening systemcomprises a displayer, a controller and a shell; openings are formed in two sides of the shell; a proximity switch is arranged at the top of the shell; an upper beam slide rail is mounted on the other side of the top of the shell, and is connected with a grinding wheel mechanism; the grinding wheel mechanism comprises a cutter sharpening base; a movable sleeve is in threaded connection into the cutter sharpening base; a grinding wheel is fixedly mounted in the movable sleeve; the cutter sharpening base is fixedly connected with a transmission mechanism; the transmission mechanism is connectedwith a two-way cutter sharpening oil cylinder; the side part of a shredding fixed cutter of the automatic cutter setting system is connected with an adjusting plate mounted on a shell fixed shaft; the adjusting plate can swing around the fixed shaft; the adjusting plate is connected with a servo motor set; the servo motor set is connected with the controller; and the adjusting plate is provided with a vibration displacement sensor set connected with the controller. The system is high in automation degree, precision and efficiency, and has the advantages of simple structure, small size, convenience to install and the like.