Sulfur dioxide is one of the main sources of atmospheric pollution.With the upgrading of national environmental protection standards,the highest emission concentration of SO₂ in flue gas is getting lower and lower.This requires upgrading the existing desulfurization process.At present,the main desulfurization methods used in industrial flue gas are dry desulfurization,semi-dry desulfurization and wet desulfurization.The technology of calcium injection desulfurization in furnace was studied.The basic components and evaluation conditions of desulfurizer were screened,and the desulfurizer was prepared for evaluation.By comparing the desulfurization effect of calcium hydroxide,calcium oxide and calcium carbonate,it was found that the desulfurization effect of calcium hydroxide was the best among them.And it was determined as the basic component of desulfurizer.In the evaluation process,the best evaluation conditions were 0.8 mL of calcium hydroxide and 200 mL/min of reaction gas.Increasing temperature was beneficial to the desulfurization of calcium hydroxide.The higher the reaction temperature was,the better the desulfurization effect of calcium hydroxide became.The desulfurization effect was better than calcium hydroxide,when ferrous oxide and manganese dioxide were introduced into calcium hydroxide.