Disclosed is a screw compressor (100), comprising a screw compressor housing (101), a discharge cavity (113), at least one silencing channel, and at least one adjustment piston, wherein the discharge cavity (113) is defined by at least one part of the screw compressor housing (101); the at least one part of the screw compressor housing (101) defining the discharge cavity (113) forms a wall of the discharge cavity (113); at least one hole is provided in the wall of the discharge cavity (113); the at least one adjustment piston can be inserted into the at least one hole and move therein; the at least one silencing channel is formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel is in fluid communication with the discharge cavity (113); and the position of the at least one adjustment piston in the at least one hole determines the silencing length of the at least one silencing channel.