The invention belongs to flue gas desulphurization technology of the environmental protection field. To solve the problems of large energy consumption, lower product quality and large investment in recovering ammonia sulfate by an ammonia desulphurization technique, the invention provides an energy-saving and high-quality ammonia desulphurization process for ammonia sulfate recovery. The process adopts ammonia water as a desulfurizer, ammonium sulfite is produced after the ammonia water and flue gas are decarbolized completely, and ammonia sulfate is produced after the ammonium sulfite is forcibly oxidized in a tower; impurities in the ammonia sulfate solution is removed by filtering, the filtrate is contacted with high-temperature flue gas in a desulfurizing tower for heat exchange, and when flue gas is cooled, the ammonia sulfate solution is heated and saturated; and then after crystallization of the saturated ammonia sulfate solution for a period of time, high-quality ammonia sulfate is produced after centrifugal drying. By adopting the technical proposal of the invention, not only thermal energy of an ammonia sulfate product which is produced by drying process can be greatly saved, high-quality ammonia sulfate fertilizer can be recovered, occupation area can be reduced and investment can be save, but also flue gas emission can meet the standard, without resulting in secondary pollution such as waste water and the like.