The invention belongs to a category of metallurgical chemical technology, in particular to a method and a device of using the gas produced by a COREX smelting reduction furnace to produce a methanol. The COREX smelting reduction furnace is not only a COREX iron smelting reduction furnace but also a gas making furnace on a methanol production line. A methanol plant uses the gas produced by the COREX smelting reduction furnace to produce the methanol; the purge gas produced in the synthesis process of the methanol is resent to a steel plant as fuel after hydrogen extraction. A gas pipeline of the COREX smelting reduction furnace is connected with the methanol plant and a purge gas pipeline of the methanol plant is connected with a hydrogen making station, and an exhaust gas pipeline is connected with a palletizing plant. Aiming at the problem of the shortage of petroleum resources in China, the invention uses the gas produced by the COREX smelting reduction furnace to produce the methanol which can not only be taken as a chemical material but also can be burned with a gasoline or made into the gasoline, thereby being beneficial to the improvement of the energy structure of China. Simultaneously, the method is also a resource of joint production of steel and coal chemical industry, which is the most economical circular economy technique in energy utilization and is the innovativetechnique of cleaning production.