NOx and CO are the key pollutants to be treated. With the further improvement of flue gas emission standards such as steel sintering, the traditional NH3-SCR (NH3 selective catalytic reduction of NOx) denitration technology has significant shortcomings, especially the sintering flue gas emission temperature is lower than the window temperature of vanadium based catalysts, causing that the activity of vanadium based denitration catalyst is insufficient and the generated ammonium sulfide blocks the catalyst surface, but there is still a lack of effective means for CO control. Therefore, the development of low-temperature catalyst has become the key factor for removing NOx and CO from low-temperature flue gas. The progress of Mn based catalyst in removing NOx and CO was discussed, the effects of active components, preparation methods and supports on the catalytic activity of Mn based low-temperature catalyst were compared, and the effects of Cu、Ce and other metals on the modification of Mn based catalyst were introduced in detail, and the relationship between element doping and catalytic performance was analyzed. On this basis, the latest research results of no reduction technology by CO in recent years were systematically combed and summarized, and the reaction mechanism and the action mechanism of O2 in the reaction were emphatically discussed. The results show that the rich extranuclear electron arrangement of Mn element is the fundamental reason for its excellent activity in removing NOx and CO, but most of the current research results are only in the laboratory theoretical stage and lack of large-scale verification in the actual flue gas. Finally, the future development direction of Mn based catalyst was prospected, and the catalyst deactivation mechanism and the scheme to improve the anti poisoning of catalyst were put forward.