NOVELTY - An inner circulation anaerobic film biological reactor comprises 1st reaction room (1) provided with water inlet pipe (12) and 1st three-phase separator (2), 2nd reaction room (3) set with film component (4) provided with water outlet and 2nd three-phase separator (5), and mud pipes (13), and gas-water separator (6) is connected to 1st reaction room, to 2nd reaction room, and to gas circulation pump (7) and film component, and is provided with biogas outlet in which 1st three-phase separator is connected to 1st gas water collection pipe (10) and gas water separator.    USE - Inner circulation anaerobic film biological reactor for treating organic wastewater (claimed). Uses included but not limited to agricultural non-staple food industry wastewater, livestock and poultry wastewater, fermentation brewing wastewater, and alcohol wastewater.    ADVANTAGE - The reactor has high load volume, compact structure, small floor area, automatic control, and simple and easy running operation and maintenance, effectively intercepts anaerobic sludge and organic pollutant, simplifies sequential treatment, increases pollutant removing rate, methane yield, and methanation rate, and achieves water discharge standard.    DETAILED DESCRIPTION - An inner circulation anaerobic film biological reactor comprises 1st reaction room provided with water inlet pipe at bottom and 1st three-phase separator at upper part and set at lower part of 2nd reaction room, 2nd reaction room set with film component provided with water outlet and 2nd three-phase separator at upper part of film component, and mud pipes at upper part of 2nd reaction room, and gas-water separator is connected to 1st reaction room through 1st return pipe (8), to 2nd reaction room through 2nd return pipe (9) in which 2nd return pipe has regulating flow structure, and to gas circulation pump and film component through aeration pipe, and is provided with biogas outlet at top part in which 1st three-phase separator is connected to 1st gas water collection pipe and gas water separator, and 2nd three-phase separator is connected to 2nd gas water collection pipe (11) and gas-water separator. An INDEPENDENT CLAIM is included for treatment of organic wastewater which involves feeding 1st and 2nd reaction rooms with anaerobic sludge, conveying organic wastewater in 1st reaction room through water inlet pipe, passing through 1st three phase separator, 2nd reaction room, 2nd three-phase separator, and gas-water separator, reflowing to 1st reaction room through 1st return pipe, reflowing to 2nd reaction room through 2nd return pipe to form inner circulation, treating mixed liquid, separating through film component to obtain produced water, separating produced methane from 1st and 2nd reaction room through 1st and 2nd three-phase separator, feeding produced methane in gas-water separator to separate produced methane, separating gas in gas-water separator, pressurizing film component with gas, and feeding gas to gas-water separator through 2nd three-phase separator to form gas circulation.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of inner circulation anaerobic film biological reactor. (Drawing includes non-English language text)    1st reaction room (1)    1st three-phase separator (2)    2nd reaction room (3)    Film component (4)    2nd three-phase separator (5)    Gas-water separator (6)    Gas circulation pump (7)    1st return pipe (8)    2nd return pipe (9)    1st gas-water collecting pipe (10)    2nd gas-water collecting pipe (11)    Water inlet pipe (12)    Mud pipe (13)