Coke oven gas is a by-product of coking plant coking process. It is a good material for preparing liquefied natural gas (LNG), but the impurities in it, especially form sulfur (such as hydrogen sulfide, sulfur oxidation of carbon, carbon disulfide, mercaptan, sulfur ether, etc.), are toxic for the synthesis of methane catalyst. The traditional flow and heat transfer process during the desulfurization process in the preparation process of LNG  with coke oven gas as raw material were introctuced; the advantages of heat-exchange process were analyzed, and the benefits of  heat transfer process were estimated.