The invention discloses a device capable of prolonging the service life of a slag fusion furnace. The device comprises an insulating brick layer, a box-hat, an amorphous layer and cooling equipment, wherein the insulating brick layer is arranged in the slag fusion furnace and is used as a contact layer of slag in the slag fusion furnace; the box-hat is arranged on the outer side of the insulating brick layer and is used for supporting and reinforcing the insulating brick layer; the amorphous layer is arranged between the insulating brick layer and the box-hat and is used for closely combining the insulating brick layer with the box-hat to facilitate heat conduction; the cooling equipment is in contact with the box-hat and is used for cooling the insulating brick layer. The original glass furnace is improved to form the device to enable the device to be suitable for slag fusion, and in addition, the device is low in manufacture cost and high in practicality and prolonged in service life.