Selective catalytic reduction technology is a mature and reliable denitrification technology, which is widely used in the removal of fixed source nitrogen oxides. The temperature window of commercial vanadium-titanium catalysts is narrow and high. In order to meet the denitration requirements of lower temperature windows in the non-power industries, low-temperature NH3-SCR has received extensive attention. In recent years, manganese-based catalysts have been regarded as the most promising low-temperature SCR catalysts due to their good low-temperature activity. The performance research of different kinds of manganese-based catalysts and the mechanism of anti-sulfur, water-resistance, alkali/alkaline-earth metal (K, Na, Ca, Mg) and heavy metal poisoning (As, Zn, Pb) on manganese-based catalysts was discussed in detail. Different anti-poisoning studies and modification methods were analyzed and summarized. The conclusions are listed as follows: ①  The best preparation method of traditional unsupported Mn-based catalysts is co-precipitation method, and the denitration efficiency is up to 100%. Microbial treatment method is a new green synthesis method, with high economic and environmental protection, which provides a feasible way for green synthesis of Mn-based catalysts. ② Doping elements such as Ce, Fe, Cu, Ni, Ho, Nd, Zr, Co, and Eu can effectively improve the denitration activity and anti-poisoning performance of Mn-based catalysts. They can be considered as "shell" materials of "core-shell" structure to improve the anti-poisoning performance of Mn-based catalysts. ③ Molecular sieve with specific pore size is an ideal material to solve the catalyst sulfur poisoning, but the problem of mass transfer resistance has not yet been solved, and the preparation method and process of molecular sieve need to be further optimized. ④ The anti-alkali metal poisoning of Mn-based catalysts is focused on doping modification. The modification strategies are divided into two categories: one is to increase the acid sites of alkali resistance on the surface of catalysts, the other is to directly inhibit the influence of alkali metals on the active components of Mn. At present, the defects of the above two modification strategies are that the modified catalyst is not economical in long-term operation of denitrification, so it is necessary to fundamentally eliminate the contact between the catalyst and alkali metals. ⑤ There are few studies on Mn-based catalysts′resistance to heavy metal poisoning. It is suggested to carry out research on the migration and transformation of heavy metals in low-temperature section and the mechanism of resistance to heavy metal poisoning by modification of Mn-based catalysts. ⑥ The poisoned catalyst is harmful to the environment, and the research on the environmental hazard assessment and renewable utilization of the poisoned catalyst also needs to be further promoted. ⑦ The synergistic effects between different types of poisoning of Mn catalysts remains to be studied tomeet the practical application requirements of Mn based catalysts.