Flue gas denitration method

The invention relates to a flue gas denitration method which comprises the following steps: S1, enabling a catalyst to be in contact with flue gas containing O2 and NOx at 100-280 DEG C for oxidation reaction, and oxidizing NO in the flue gas into NO2 to obtain oxidized flue gas; s2, enabling the oxidized flue gas to be in contact with absorption liquid for oxidation absorption, wherein the absorption liquid contains hydrogen peroxide and nitric acid; wherein the catalyst contains nano composite material particles with core-shell structures, the nano composite material particles comprise nickel oxide cores and graphitized carbon shells coating the outer surfaces of the nickel oxide cores, and the carbon content of the nano composite material particles is not greater than 5 wt% by taking the total weight of the nano composite material particles as a reference. The method provided by the invention can effectively reduce the temperature of denitration treatment on the premise of ensuring the denitration effect.