Single-screw extruder

The invention discloses a single-screw extruder, which comprises an extruder rack, a driving motor, an elastic shaft coupling, a reduction gearbox, a bushing, a discharging seat, a barrel and a screw, wherein the driving motor is arranged on the extruder rack, and is connected with the reduction gearbox through the elastic shaft coupling; the reduction gearbox is connected with the screw; the screw is arranged in the bushing and the barrel; the discharging seat is arranged on the bushing; a single-stage transmission mechanism is adopted for the reduction gearbox, and the reduction gearbox is provided with a damping mechanism; the length-to-diameter ratio of the screw is 35:1 to 40:1. The single-screw extruder is energy-saving, the yield can be effectively improved, and noise can be reduced.