The well type furnace liner is made of high temperature resistant stainless steel plate, which is rolled into a cylinder, processed into corrugations and welded to increase the overall strength of the furnace liner. The furnace liner cover and flange are made of δ = 30mm Q235A steel plate and machined by lathe. The heat-resistant rubber is selected as the sealing ring between the furnace liner cover and flange. The water-cooling sleeve is set on the furnace liner cover and flange to better protect the heat-resistant rubber sealing ring. The installation pressure of - 0.1MPa is set on the furnace liner cover To + 0.3MPa pressure gauge, high temperature exhaust ball valve, 0.03-0.003mpa safety valve and other instruments, lifting hook, etc., and 200-250mm thick silicon cotton is embedded under the cover for thermal insulation.