Abstract: With the continuous strengthening of environmental protection control,the content of nitrogen oxides in the flue gas emitted by some aluminum smelting industries could not meet the latest requirements of the state on the emission concentration of air pollutants. Combined with the current situation of the flue gas emission in aluminum smelting industry,the technical problems such as process selection,equipment composition,layout form and control system of denitration transformation were analyzed and discussed,and the feasible transformation scheme was given,which provided reference for the treatment of out-of-stock flue gas in aluminum smelting furnace.