With the aim of alleviating the problems of air pollution, soil desertification, and food shortages in China, we have studied the impact of reclamation of alkali soil using the by-products of flue gas desulfurization (FGD). We have developed an evaluation model for assessing the complete economic and environmental impact of the introduction of environmental improvement technologies. The model consists of an economic model based on an input-output table for China and a soil reclamation model. In the context of the introduction of FGD equipment, we are able to calculate the associated changes in economic variables such as real GDP, average wage, labor supply, domestic electricity price, real investment other than for desulfurization equipment, investment in construction, SO2 emissions in provinces and cities, area of reclaimed alkali soil, and corn and rice production. We simulated the introduction of the wet limestone-gypsum process and/or the integrated desulfurization and water-film dust collection process. The results confirm a reduction in SO2 emissions and increases in GDP, domestic electricity price, and agricultural production following soil reclamation via the application of desulfurization by-products. In summary, our results confirm the effectiveness of these desulfurization technologies in terms of improving the economy and environment in China.