NOVELTY - The biogas desulfurization device comprises an anaerobic system, a desulfurization liquid circulating system (10, 12), an oxygen supply device (9), and a desulfurization system. The anaerobic system is configured for generating biogas and for filling the generated biogas into the desulfurization system, and comprises anaerobic digesters. The desulfurization liquid circulating system is configured for filling the desulfurization liquid into the desulfurization system and for recycling the desulfurization liquid that is undergone the desulfurization operation.    USE - The device is useful for desulfurization of biogas.    ADVANTAGE - The biogas desulfurization device is simple and convenient to operate, efficiently reduces the amount of hydrogen sulfide in the biogas to less than 10 ppm through repeated desulfurization operation, and eliminates secondary pollution through self-circulation and metabolization of microbes.    DETAILED DESCRIPTION - The biogas desulfurization device comprises an anaerobic system, a desulfurization liquid circulating system (10, 12), an oxygen supply device (9), and a desulfurization system. The anaerobic system is configured for generating biogas and for filling the generated biogas into the desulfurization system, and comprises anaerobic digesters. The desulfurization liquid circulating system is configured for filling the desulfurization liquid into the desulfurization system and for recycling the desulfurization liquid that is undergone the desulfurization operation. The oxygen supply device is configured for filling air into the desulfurization system. The desulfurization system that comprises two stages desulfurization tower groups is configured for carrying out the desulfurization operation on the biogas from the anaerobic system. The desulfurization operation is conducted by the desulfurization liquid received from the desulfurization liquid circulating system in an aerobic environment formed after the air is filled by the oxygen supply device. The number of the anaerobic digesters corresponds to the number of desulfurization towers (1, 2, 3, 4) in a first stage desulfurization tower group of the desulfurization system. Each of the anaerobic digesters is correspondingly connected to one of the desulfurization towers in the first stage desulfurization tower group so as to supply the biogas to the desulfurization towers. The first stage desulfurization tower group comprises four desulfurization towers, and a second stage desulfurization tower group (11) comprises one desulfurization tower. The desulfurization towers comprise a gas inlet, a gas outlet, a desulfurization liquid inlet, a desulfurization liquid outlet, and an internal filler. The gas inlet and the desulfurization liquid outlet are arranged at a bottom part of the desulfurization towers. The gas outlet and the desulfurization liquid inlet are arranged at a top part of the desulfurization towers. The gas outlet of the four desulfurization towers of the first stage desulfurization tower group are connected with each other and connected to a gas inlet of the desulfurization tower of the second stage desulfurization tower group. The desulfurization liquid circulating system comprises a desulfurization liquid tank, a circulating pump and a spraying device. The circulating pump is configured for drawing the desulfurization liquid from the desulfurization liquid tank and supplying the desulfurization liquid to the spraying device. The spraying device is arranged at the position of the desulfurization liquid inlet, and is configured for filling the desulfurization liquid into the desulfurization towers. The desulfurization liquid outlet is connected to the desulfurization liquid tank so as to recycle the desulfurization liquid that has undergone the desulfurization operation to the desulfurization liquid circulating system. The oxygen supply device comprises an air compressor and a throttle valve. The air compressor is configured for filling air into the desulfurization tower. The throttle valve is configured for controlling the amount of the air filled in the desulfurization tower.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a biogas desulfurization device.    Desulfurization towers (1, 2, 3, 4)    Anaerobic digesters (5, 6, 7, 8)    Oxygen supply device (9)    Desulfurization liquid circulating system (10, 12)    Second desulfurization tower group. (11)