Abstract: With a case study of coal fired power plants, and based on the definition of goal and scope, the emission inventory analysis and environment impact evaluation were performed for limestone-gypsum wet flue gas desulphurization (WFGD) technology. From the viewpoint of the whole life cycle, there exist environmental problems in limestone-gypsum WFGD, including dust, noise and ecological destruction, etc. The ecological restoration cost and the cost for harmless treatment of desulphurization gypsum and desulphurization wastewater are far higher than the FGD cost currently evaluated. Considering China’s current energy structure and environmental status, the limestone-gypsum FGD technology is not sustainable, and the flue gas recycling technology with cascade utilization should be worthy of demonstration and dissemination.