NOVELTY - A semi-ground anaerobic reaction tank, comprises a reaction tank main body (1), a reaction tank bottom plate (2), and a reaction tank top plate (3); where the top part of the reaction tank top plate (3) is formed with a man hole (4); the man hole (4) is set with an assorted sealing cover (5); the sealing cover (5) is formed with an exhaust hole; the exhaust hole is connected with an exhaust pipe (6); and the two sides of the lower end of the reaction tank main body (1) are set with a water inlet pipe (7) and a drain pipe (8).    USE - The semi-ground anaerobic reaction tank is useful for sewage treatment process.    ADVANTAGE - The semi-ground anaerobic reaction tank has rational structure design and high safety; and it is durable and firm. Moreover, it has good inner circulation property in the sewage treatment process. Additionally, it has good sewage treatment effect, large biogas yield, convenient installation, and wide application range.    DETAILED DESCRIPTION - A semi-ground anaerobic reaction tank, comprises a reaction tank main body (1), a reaction tank bottom plate (2), and a reaction tank top plate (3); where the top part of the reaction tank top plate (3) is formed with a man hole (4); the man hole (4) is set with an assorted sealing cover (5); the sealing cover (5) is formed with an exhaust hole; the exhaust hole is connected with an exhaust pipe (6); the two sides of the lower end of the reaction tank main body (1) are set with a water inlet pipe (7) and a drain pipe (8); one side of the lower end of the reaction tank main body (1) is connected with a circulation pipe (9) having pump; the other end of the circulation pipe (9) is located on the upper end of the reaction tank main body (1); and the side surface of the reaction tank main body (1) higher than the upper end of the circulation pipe (9) is connected with an overflowing pipe (10).    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the semi-ground anaerobic reaction tank.    Reaction tank main body (1)    Reaction tank bottom plate (2)    Reaction tank top plate (3)    Man hole (4)    Assorted sealing cover (5)