NOVELTY - Integrated desulfurization and denitrification method includes converting nitrogen oxide to nitrogen dioxide, introducing the oxidation zone in the concentrate solution of ammonium sulfate and ammonium nitrate, concentrating, evaporating concentrate and crystallizing, and using a mixture of flue gas into the absorption section of the spray layer, a mixture of ammonium sulfite and ammonia spray layer on the spray mixture of the flue gas sulfur dioxide, and nitrogen dioxide fast absorption reaction of ammonium nitrate and ammonium sulfate to achieve desulfurization and denitrification.    USE - Integrated desulfurization and denitrification method.    ADVANTAGE - The method is simple, energy-saving and environment-friendly, and has low cost.    DETAILED DESCRIPTION - Integrated desulfurization and denitrification method comprises:    (A) making the desulfurization tower in the middle of one side of the flue gas desulfurization tower according to the desulfurization tower from the bottom having concentrated oxidation zone and absorption section, according to the absorption section from top under the order process water spray layer, the oxide layer and having a mixture of ammonium sulfite and ammonia mixture of spray layer;    (B) conversion of nitrogen dioxide (NO2) with a flue gas inlet at the position of the desulfurization tower to achieve the conversion of nitrogen oxide (NO) to (NO2);    (C) introducing NO containing flue gas inlet and SO2 in the flue gas into the desulfurization tower oxide concentration section, allowing the conversion of NO2 in the flue gas, converting NO to NO2 and generating the corresponding ammonium nitrate (NH4NO3), and generating ammonium sulfate ((NH4)2SO4) fertilizer hybrid type;    (D) introducing the oxidation zone in the concentrate solution of (NH4)2SO4 and NH4NO3, and concentrating the solution using an evaporator to cool the flue gas, while concentrating the liquid by evaporation of the synthetic crystalline byproducts fertilizer;    (E) evaporating liquid concentrate to provide (NH4)2SO4 and NH4NO3 solution into the oxidation concentrate, cooling the synthetic liquid, evaporating concentrate and crystallizing the synthetic liquid to provide a fertilizer by-product; and    (F) using a mixture of flue gas into the absorption section of the spray layer, a mixture of ammonium sulfite and ammonia spray layer on the spray mixture of the flue gas SO2, NO2 fast absorption reaction of NH4NO3 and (NH4)2SO4 to achieve desulfurization and denitrification; then followed by flue gas into the process water spray layer absorbing segment, using the process water spray layer of water on the reaction process and preventing the escape of ammonia.