In recent years, frequent haze has made PM_2.5 become a public hotspot. PM_2.5 control has been added to the 2012 release “ambient air quality standard.” Currently flue gas pollutant control technology does not easily remove PM_2.5. Developing Flue Gas Pollutant Deep-removal Technology (DRT) for coal-fired power plants for deep-removing pollutants such as PM_2.5, SO₂, SO₃, and heavy metals, is an urgent problem. Based on the analysis of the necessity and existing problems of developing DRT suitable for China, this study focused on PM_2.5 removal technology, low NO_x emission of ultra supercritical boiler under all load conditions, and the adaptability of SCR working temperature. Finally, the flue gas pollutant removal system at a 2×660MW supercritical power plant was introduced, and the roadmap for developing DRT for 1,000MW ultra supercritical units was analyzed.