Gas extraction exhaust device used for allowing aluminum alloy casting mould sand core to exhaust

A gas extraction exhaust device used for allowing an aluminum alloy casting mould sand core to exhaust comprises a device body which is installed on a gas extraction pipeline of a mould and used for allowing the sand core to exhaust. Stepped holes are formed in the middle of the device body and comprise the large stepped hole corresponding to the sand core and the small stepped hole connected with the large stepped hole, filler used for filtering flue gas is installed in the large stepped hole, and an exhaust plug is installed in the small stepped hole. A coating layer used for preventing liquid aluminum from being pasted on the filler is arranged at the end, making contact with the sand core, of the device body. At present, core head parts of all aluminum alloy casting moulds with sand cores are provided with exhaust plugs in order to facilitate exhaust of the sand cores; however, the exhaust plugs for exhaust of the existing sand cores are high in manufacturing difficulty and poor in exhaust effect, cannot be cleaned up easily and need moulds to be detached during replacement, thereby affecting production efficiency. The gas extraction exhaust device is simple in structure, convenient to use, high in durability and capable of achieving quick installation and quick replacement under the situation of continuous production.