NOVELTY - A straw marsh gas fermenting tank comprises outer tank body, inner container, collecting box, where inner bottom of the tank body is equipped with water collecting grooves (4), the water collecting grooves are internally mounted with a water pumping pipe, the upper part in inner container is mounted with spraying pipe, the spraying pipe is provided with multiple spraying openings, the water pumping pipe and the spraying pipe are connected by the circulation spraying pipeline, and a biogas outlet is provided at the top of the tank body.    USE - As a straw marsh gas fermenting tank (claimed).    ADVANTAGE - The fermenting tank solves the problem of inlet and outlet material difficult to set the circular spraying device, which solves the problem of stirring; and is able to save the cost.    DETAILED DESCRIPTION - A straw marsh gas fermenting tank comprises outer tank body (3), an inner container (2) clung to the inner wall of the tank body, at least one collecting box arranged in the inner container, where inner bottom of the tank body is equipped with water collecting grooves (4), the water collecting grooves are internally mounted with a water pumping pipe, the upper part in the inner container is mounted with a spraying pipe, the spraying pipe is provided with multiple spraying openings, the water pumping pipe and the spraying pipe are connected by the circulation spraying pipeline, the upper part of the suction pipe is provided with a pneumatic stirring tube, the air inlet of the pneumatic stirring tube passes through the tank body, pneumatic stirring pipe is equipped with multiple air outlets, and a biogas outlet is provided at the top of the tank body. The inner container is made of polymer composite material. The inner container adopts polyvinyl chloride bi-poly-bi-, rubber, artificial tendon or composite material.    DESCRIPTION OF DRAWING(S) - The figure shows a view of the straw marsh gas fermenting tank.    Inner container (2)    Tank body (3)    Water collecting groove (4)    Pneumatic force stirring pipe (8)    Cone-shaped groove (70)    Waste outlet opening (71)    Water inlet pipe (81)    Water inlet branch pipe (82)