NOVELTY - The anaerobic reactor comprises a fermenting tank whose upper part is divided into efficient area and purification area, where the purification area is arranged adjacent to the efficient area. An upper part of the efficient area is connected with a feeding tank whose lower part is provided with a feeding tube. A lower end of the feeding tube is extended to an inner lower part of the efficient area. The upper part of the fermentation tank is provided with an uplink return tube that is connected with a gas-liquid separator. The gas liquid separator is connected with two path ways.    USE - The anaerobic reactor is useful for treating animal corpse (claimed).    ADVANTAGE - The anaerobic reactor can be operated rapidly, saves manpower and avoids secondary pollution, utilizes less resource, and has good emission reduction effect.    DETAILED DESCRIPTION - The anaerobic reactor comprises a fermenting tank whose upper part is divided into efficient area and purification area, where the purification area is arranged adjacent to the efficient area. An upper part of the efficient area is connected with a feeding tank whose lower part is provided with a feeding tube. A lower end of the feeding tube is extended to an inner lower part of the efficient area. The upper part of the fermentation tank is provided with an uplink return tube that is connected with a gas-liquid separator. The gas liquid separator is connected with two path ways. One path is connected with a gas tube and a cover, and another way is passed through a return tube. A return switch is connected with the return tube. The return tube is connected with a strong reflux switch provided with a strong return tube. A return tube pipeline is connected with a reflux pump, the return tube and the feeding tube. A middle part of the purification area is provided with a first water pumping pump that is connected with a cutting machine. The cutting machine is connected with a water adjusting tank through a diving pump. A second water pumping pump is connected with the feeding tank. A lower end of the feeding tube is provided with an inclined section. A lower part of the purification area is provided with an overflow tube. The efficient area and the bottom part of the purification area are respectively provided with a first bottom slag discharging tube, a second bottom slag discharging tube.