Abstract:With the transformation of the two kinds of FGD technology practice in a mining company, the paper introduced the reaction principle of wet limestone-gypsum and dual-alkali in FGD process.Through some comparisons that production and technical indication、lime consumption and power consumption of the practical data among the two, the reasons for the selection of wet limestone-gypsum method for the technical modification of the company were discussed.Compared with the dual-alkali method, the wet limestone-gypsum process were used for desulfurization. not only was the environmental protection up to the standard, the production and technical indication was excellent, but the annual cost saving was 2 million 850 thousand and 600 yuan,and the results were remarkable.