Abstract: A fermentation device includes a fermenter. The fermenter includes a tank, augers, and a motor. The tank is horizontally arranged. A first end of the tank is connected with a material feeding port. A second end of the tank is connected with a material discharging port. A height of the material discharging port is not less than a height of the tank. Liquid raw material and solid raw material are added into the tank from the material feeding port. The augers are arranged in the tank. Each of the augers includes a central shaft and a blade. An inner edge of each blade is connected with a corresponding central shaft. A gap is defined between an outer edge of each blade and inner walls of the tank. The motor is connected with the augers and drives the augers to rotate in a first direction or a second direction.