The more stringent new standard of air pollutants for thermal power plants was promulgated to solve the severe air pollution problem. The updating and retrofitting action on energy saving and emission reduction for coal-fired power plants was required to be executed to balance the contradiction between the development of coalfired power plants and the environmental protection. The state of the art and existing problems of pollutants emission control in existing coal-fired power plants were analyzed. Different processes of ultra-low emission control technologies with low-low temperature electrostatic precipitator and/or wet electrostatic precipitator were introduced and the potential problems on each process were analyzed. Some suggestions on development of the flue gas ultra-low pollutant emission control technology were presented. It is necessary to conduct the assessments of the technical

economic and environmental performances for the project demonstrations of ultra-low emission technology with different processes and to determine the application limit of each removal process. The optimal process of ultra-low pollutant emission technology for different large scale coal-fired power plants can be applied efficiently and economically.