Methane fermentation reactor

The utility model discloses a methane fermentation reactor, which comprises a casing, at least one inlet, at least one outlet and a heating coil, wherein the a liquid storage cavity is limited in the casing and used for accommodating to-be-fermented methane liquid; the inlet and the outlet are arranged on the casing respectively; and the heating coil is arranged outside the casing and is in contact with the casing. By the adoption of the outer heating coil, the corrosion of an inner coil is avoided, and the temperature necessary for winter fermentation can be guaranteed. The methane fermentation reactor is suitable for heating and fermenting methane liquid acquired from straws of such crops as wheat, paddy rice, corns, soybeans and the like to generate methane, and is favorable for large-scale industrialized production.