NOVELTY - A treatment device for waste biogas liquid comprises separation device (1) arranged below a biogas fermentation tank (14), a fermentation tank (2), and a cover board (7). Lower end side wall of the biogas fermentation tank is connected with the separation device through a waste biogas liquid effusing pipe (4). Liquid outlet on the side wall of the fermentation tank is connected with inlet of sewage pump (10). The outlet of the sewage pump is connected with one end of delivery pipe (11) while the other end of the delivery pipe is connected with the upper end of the biogas fermentation tank.    USE - A treatment device for waste biogas liquid.    ADVANTAGE - The device solves the problems that the existing process for treating waste biogas liquid has high cost of purifying the waste biogas liquid and is easy to cause secondary pollution. The device has simple structure, low production cost, less land use, high intensity and convenient construction. The treatment method is simple, has convenient operation, reduces the purification cost, and purifies the environment when producing biogas as energy.    DETAILED DESCRIPTION - A treatment device for waste biogas liquid comprises a sewage pump (10), a delivery pipe (11), a waste biogas liquid effusing pipe (4), a separation device (1), a fermentation tank (2) and a cover board (7). The separation device is composed of a funnel-shaped shell (17), a slag cleaner (5) and a filter mesh (6). The slag cleaner and filter mesh are arranged into the columnar cavity on the upper part of the funnel-shaped shell in turn from up to down. The cover board is arranged on the upper end surface of the fermentation tank and connected with the fermentation tank in sealing way. The separation device is arranged below a biogas fermentation tank (14). Lower end side wall of the biogas fermentation tank is connected with the separation device through the waste biogas liquid effusing pipe. Lower end of the funnel-shaped shell is mounted on the cover board and connected with the fermentation tank. The liquid outlet on the side wall of the fermentation tank is connected with the inlet of the sewage pump. The outlet of the sewage pump is connected with one end of the delivery pipe while the other end of the delivery pipe is connected with the upper end of the biogas fermentation tank. An INDEPENDENT CLAIM is included for treating the waste biogas liquid by using the treatment device comprising infusing the waste biogas liquid obtained by filtering the residual substances produced by fermenting the biogas through the separation device into the fermentation tank, at the same time feeding composite bacterial agent into the fermentation tank to ferment for 18-20 hours, and then fully refluxing to the biogas fermentation tank for fermenting biogas, completing the treatment of waste biogas liquid; where the inoculum size of the composite bacterial agent is 0.5-1 mass%, and the composite bacterial agent is composed of lactic acid bacteria and saccharomycetes at a number ratio of 100: 1.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram illustrating the waste biogas liquid treatment device.    Separation device (1)    Fermentation tank (2)    Waste biogas liquid effusing pipe (4)    Slag cleaner (5)    Filter mesh (6)    Cover board (7)    Sewage pump (10)    Delivery pipe (11)    Biogas fermentation tank (14)    Funnel-shaped shell (17)