The invention discloses a method for refining fuel ethanol by integrating materials and heat through coupling towers with a membrane. The method is characterized in that a rectification-purification technology system composed of a three-tower rectification section formed by connecting reduced pressure crude distillation tower with a pressured rough distillation tower in parallel and then connecting the two distillation towers with a pressurized rectification tower in series and a purification section formed by a membrane separation device highly matches the material and heat systems of the rectification section and the purification section to reduce the amount of steam for per unit of the product, and steam penetration membrane separation is combined to reduce the requirements for the concentration of the fed ethanol, reduce the plate number of the pressurized crude distillation tower and reduce the reflux ratio, so a biomass fermentation liquid is rectified and purified to prepare highly pure ethanol meeting the requirements of fuel ethanol and achieve the purpose of environmentally-friendly, energy-saving and efficient production. The method of the invention has the advantages ofgreat saving of the use amount of the steam, high quality of the one-time discharged product, high automation degree of the system, small occupied area of a device, convenience in device maintenance,reliable and durable membrane consumable materials, and high resource utilization rate.