Method for denitrating flue gas of power plant and absorption liquid used by method

The invention discloses a method for denitrating flue gas of a power plant and an absorption liquid used by the method. The method for denitrating the flue gas of the power plant comprises the following step of: ensuring that NO is oxidized in an absorption tower and is further absorbed by the absorption liquid so as to finish the denitration of the flue gas of the power plant by utilizing the absorption tower and using a Fenton-like reagent and an aqueous solution as the absorption liquid under the condition that the temperature is controlled to be 30 to 80 DEG C, wherein the Fenton-like reagent consists of H2O2 and ferric sulfate; and ethylene diamine tetraacetic acid (EDTA) is taken as an additive in the aqueous solution. In the absorption liquid, the concentration of H2O2 is 0.5 to 1mol/L; the concentration of Fe2(SO4)3 is 0.01 to 0.025mol/L; the concentration of the additive, namely the EDTA is 0.02 to 0.05mol/L; and the pH value of the absorption liquid is 5 to 6. The method for denitrating the flue gas of the power plant is simple and high in denitration efficiency, and secondary pollution is avoided.