NOVELTY - Usage method of coke oven for preparing methane involves subjecting methanation raw material carbon material containing brown coal, and coke oven gas to dry distillation as follows. Coke-oven gas is purified, modified, decarburized, pressurized, mixed with recycle gas, obtained raw material gas and reaction-generating gas are heated, passed into methanation reactor, methanation carbon material is preheated. Waste heat boiler is connected with resultant raw material gas and cold water, heat-exchanged, then, resultant product is separated and purified, to obtain recycle gas and product gas.    USE - Usage method of coke oven for preparing methane (claimed).    ADVANTAGE - The methane is prepared using the coke oven, with reduced hydrogen consumption and impact on environment, and high yield.    DETAILED DESCRIPTION - Usage method of coke oven for preparing methane involves subjecting methanation raw material carbon material containing brown coal or long flame coal and coke oven gas at 400-700 degrees C to dry distillation, such that mass content of obtained ash without water and oxygen element is less than 7%, mass concentration of hydrogen element is more than 4.5% and mass content of carbon element is more than 84%. The coke-oven gas is purified, modified, decarburized, pressurized to 2-10 MPa and mixed with recycle gas in volume ratio of 1:5-2:1, to obtain mixed raw material. Then, raw material gas and reaction-generating gas are heated at 45-650 degrees C, obtained product are passed into methanation reactor, and methanation carbon material is preheated at 350-650 degrees C from bottom of methanation reactor and 70-100 degrees C from top of methanation reactor under pressure of 2-10 MPa, to obtain reaction-generating gas and raw material gas. The reaction-generating gas is discharged from upper portion of methanation reactor. Waste heat boiler is connected with raw material gas and cold water, heat-exchanged, the temperature is reduced to 30-50 degrees C, then, resultant product is separated and purified, to obtain recycle gas and product gas. Then, recycle gas is returned to raw material gas, and the product gas is discharged.