NOVELTY - Producing methanol comprises e.g. collecting waste water generated in Lurgi coal gasifying and cooling in a filter pool, pumping upper layer of waste water to a pH regulating pool, adding raw material coal, waste water, additive and co-solvent to obtain coal slurry, atomizing and spraying slurry and oxygen into a water-coal-slurry gasification furnace, mixing the wet coal gas of the water-coal-slurry gasification and Lurgi coal gasification furnaces, sending the gas into a moderate change furnace, desulfurizing/decarbonizing, and dividing the gas into carbon monoxide and hydrogen.    USE - The method is useful for producing methanol by treating Lurgi coal gasified waste water.    ADVANTAGE - The method is capable of economically and safely treating high concentration of Lurgi coal gasified waste water in an environment-friendly manner.    DETAILED DESCRIPTION - Producing methanol by treating Lurgi coal gasified waste water using a water-coal-slurry gasification furnace, comprises: (a) collecting waste water generated in Lurgi coal gasifying and cooling in a filter pool, standing for 24 hours to remove fine ash, and pumping the upper layer of concentrated waste water to a pH value regulating pool; (b) regulating the pH value of the waste water to 6.8-7.2 using a pH regulating agent; (c) adding raw material coal, waste water, additive and co-solvent into a coal mill to obtain coal slurry, where the viscosity of the coal slurry is 300-1200 cP, the coal slurry concentration is 58-62% and the granularity of the coal slurry is 8-325 meshes; (d) atomizing and spraying the coal slurry and oxygen with a purity of more than 99.6% into the water-coal-slurry gasification furnace under high pressure through a nozzle to generate wet coal gas with carbon monoxide, hydrogen and water; (e) mixing the wet coal gas of the water-coal-slurry gasification furnace and the Lurgi coal gasification furnace after washing and cooling, and sending the product into a moderate change furnace or a deep change furnace, where the moderate change furnace is used to change one part of carbon monoxide in the wet coal gas into carbon dioxide for satisfying the requirement of carbon monoxide content for producing methanol; (f) desulfurizing or decarbonizing the changed gas, removing hydrogen sulfide and carbon dioxide gas through wet desulfurizing method, and removing organic sulfur via fine desulfurizing method; and (g) dividing the desulfurized and decarbonized gas into carbon monoxide and hydrogen, regulating the proportion of carbon monoxide to hydrogen, compressing the mixture using a compressor, passing it into the methanol synthesizing stage to synthesize methanol, and performing nitrogen-hydrogen compression reaction using nitrogen to generate liquid ammonia.    DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of a method for producing methanol.