NOVELTY - &gt;The method comprises disposing the solid and liquid organic waste in a reactor, filling a theoretical oxygen content (less than 0.1-0.3 times) into the reactor, heating and pressurizing the waste, controlling the reaction temperature above 374 degrees C and the reaction pressure to greater than 22 MPa, performing gas-liquid separation of the gas-liquid mixture, conveying the liquid phase into another catalytic methane-type reactor filled with a catalyst, and controlling the reaction temperature above 374 degrees C and the reaction pressure of higher than 22 MPa.    USE - The method is useful for disposing solid-liquid organic waste, which is useful for producing fuel gas, where the solid organic waste includes waste of aerobic, anaerobic and sewer sludge series, kitchen garbage, paper, plastic, wood chips, bamboo chips, grass pieces, straws, fibers, vegetable leaves, rubber, skin, food processing waste, livestock waste, and agricultural, forestry and aquatic waste and the liquid organic waste includes domestic wastewater, the wastewater from food processing factories, the wastewater from animal houses/ chicken farms, biological industrial wastewater difficult to be processed and alcohol/aldehyde wastewater (claimed).    ADVANTAGE - The method is capable of economically and simply disposing the solid-liquid organic waste with reduced energy consumption in a convenient manner.    DETAILED DESCRIPTION - The method comprises disposing the solid and liquid organic waste in a reactor, filling a theoretical oxygen content (less than 0.1-0.3 times) into the reactor, heating and pressurizing the waste, controlling the reaction temperature above 374 degrees C and the reaction pressure to greater than 22 MPa, performing gas-liquid separation of the gas-liquid mixture, conveying the liquid phase into another catalytic methane-type reactor filled with a catalyst, controlling the reaction temperature above 374 degrees C and the reaction pressure of higher than 22 MPa, contacting and reacting the liquid with the catalyst and then conveying reacted flow into a gas-liquid separator to perform the gas-liquid separation to obtain the combustible mixed gas mainly containing methane and hydrogen, removing mud residue and the metal elements, returning one part of the separated liquid phase into the reactor after finishing the gas-liquid separation, conveying the left part to the downstream to process, recycling a gas phase dynamically after the gas-liquid separation, flocculating and precipitating the liquid conveyed to the downstream and then removing the metal elements from the liquid, conveying the separated water phase into the reactor to perform heat exchange with the unreacted organic material liquid after the gas-liquid separation and then conveying parts or the whole of the left into a storage kettle to serve as slurry diluting water of the solid organic waste, thermally or dynamically recycling the combustible mixed gas and then removing carbon dioxide from the combustible mixed gas by pressure swing adsorption, film separation or alkali liquid absorption. An object processed by the reaction comprises the solid organic waste, the liquid organic waste, mud slurry of organic waste and water, or the mud slurry containing an organic compound. The linear speed of the liquid in the reactor is 0.01-0.1 cm/sec. The amount of the separated liquid phase returned to the reactor after the gas-liquid separation is 10-20 times of the amount conveyed to the downstream. The catalyst has a spherical shape, a pill-like shape, a columnar shape, a powdered shape or a honeycomb shape, and employs the honeycomb structure. An opening part of the honeycomb structure has a four-corner shape, a hexagonal shape or a circular shape. The grain diameter of the catalyst is 3-50 mm. The filling unit area of the catalyst is 200-800 square meters per cubic meter. The porosity of the catalyst is 40-80%. The linear speed of the liquid in the catalytic methane-type reactor is 0.1-1.0 cm/sec. The carbon dioxide removed from the combustible mixed gas is conveyed into an alkali liquid absorbing tower and a carbon dioxide regenerating tower. The alkali liquid recycled by the carbon dioxide regenerating tower is conveyed into the alkali liquid absorbing tower again. The pressure of the alkali liquid absorbing tower is higher than the atmosphere pressure. The pressure in the carbon dioxide regenerating tower is lower than the atmosphere pressure.