The invention discloses a method for synthesizing natural gas through magnetizing hematite by coke-oven gas. The method comprises the following steps of adding hematite powder with particle sizes less than or equal to 2mm into a reactor with a stirring structure, heating, then feeding coke-oven gas for a magnetization reaction, after the coke-oven gas undergoes the magnetization reaction, carrying out decarburization and dehydration to obtain natural gas, wherein non/ weak magnetic Fe2O3 in the hematite powder is reduced to magnetic Fe3O4, carrying a direct pulping process or a wet grinding pulping process on the hematite powder subjected to the magnetization reaction, feeding the pulp obtained by the previous step into a magnetic separator for sorting, and carrying out magnetic mineral dehydration to obtain iron-containing concentrate. Through the method, hematite reduction magnetization and preparation of methane-rich synthetic gas by removal of CO/H2 from coke-oven gas are integrated optimally and thus two purposes are realized simultaneously. The method has simple processes, a low investment cost, good adaptability for all types of hematite, easy sorting of magnetized mineral, high iron concentrate product quality, and good economical efficiency.