In coal-fired, cement and waste incineration plants, water vapour and SO_2 contained in the flue gas could easily lead to poisoning and deactivation of the catalyst under low-temperature environments. Therefore, addressing low-temperature anti-water vapour and SO_2 poisoning has become a critical technical challenge. Firstly, the technical difficulties faced by NH_3-SCR denitrification catalysts in industrial low-temperature environments are analyzed, including the mechanisms of water vapour and SO_2 poisoning, and then the research strategies to improve the water and SO_2 resistance of catalysts in recent years are elaborated in depth. It includes designing hydrophobic coatings and using elemental synergism to improve the electronic structure of the catalyst surface, etc. to inhibit the adsorption and oxidation of SO_2; using acidic sites and redox-active sites to promote the decomposition of ammonium bisulphate salts; and adding sacrificial agents to improve the stability of the catalyst. Finally, the strategies for improving the anti-poisoning were summarised and prospected, aiming to provide insights into the design and preparation of low-temperature flue gas denitrification catalysts with high efficiency, strong anti-poisoning ability and long service life.