The widely used flue gas desulfurization technology was introduced, and the principle and process of ammonia desulfurization are introduced were analyzed in detail. Based on the principle of the ammonia desulfurization, the selection of cycle absorption desulfurization section and neutralizing ammonia injection point, the distribution of oxidation reaction, and the key details of design of inlet and outlet pipeline of salt absorption tank were expounded. Combined with the practical operation experience of the device, the problems of flue gas desulfurization , such as chimney tail towing  were analyzed, and the corresponduring solutions were proposed. The key links and parameters of the design and operation process, including the gas phase linear velocity, PH value, spray density, temperature and so on were analyzed and some suggestions for improvement were put forward.