Abstract: The situation of atmospheric environmental in China is severe，the relevant state policies，standards become more and more strict，and the flue gas“ultra-low emissions”of coal-fired power plant is imperative． But there are not a standard test method for low concentration of flue gas in coal-fired power plants． This paper mainly introduced the foreign standards of low concentration test method，and through the actual test，low concentration testing instruments and methods was studied， aiming to explore a scientific and reasonable low concentration testing techniques and methods，and provide certain reference for the selection of standard test method in China．