The invention discloses a method for separating and concentrating methane in coke oven gas. The method comprises the following steps: introducing pressurized coke oven gas into a cooled tetrahydrofuran water solution so that the methane in the coke oven gas and the tetrahydrofuran water solution react to generate a solid hydrate, wherein the reaction is performed in a reactor; after the reaction finishes, evacuating gas in the reactor; and heating the solid hydrate for decomposition to obtain the methane, thereby implementing the separation of the methane in the coke oven gas. Compared with the low-temperature cryogenic separation process, the method lowers the energy consumption required by the gas separation system (the low-temperature separation is usually performed at -160 DEG C or so, but the operating temperature of the invention is basically normal temperature). Compared with the traditional separation process, the method has the advantages of simple required equipment and low gross investment. The pressure loss of the coke oven gas is small to ensure the methane-rich gas to be decomposed by heating under high pressure, thereby ensuring the gas pressure and avoiding secondary pressurization.