Inner lining composite structure of blast furnace casting hole

A blast furnace taphole lining combined structure belongs to the technical field of iron-smelting blast furnace apparatuses, which is particularly adaptable to ultra large blast furnace. The blast furnace taphole lining combined structure comprises a blast furnace and a taphole arranged on the blast furnace, the taphole comprises a taphole frame, four corundum-mullite composite bricks in the taphole frame, a furnace door iron frame, taphole brick covers and taphole castable, and the taphole brick covers are wedge-shaped. The combined structure can increase structural strength and structural sealing property of the taphole, solves the problem of back blowing at the taphole, and increases service life of the taphole and further guarantees iron tapping safety.