To solve the issues existed in the traditional deep denitrification treatment technology for Municipal Solid Waste Incineration flue gas, such as complex system, large investment and high operating cost, a new method of deep denitrification by narrow pulse discharge reaction coupling with wet adsorption was proposed. The deep denitration of municipal solid waste incineration flue gas via the non-thermal plasma generated by the self-developed nanosecond pulse power corona discharge was studied. The results show that the removal efficiency of NO and NO_x was enhanced when the power supply frequency and residence time were increased. Under the case with single corona discharge reactor when the peak voltage is 82 kV, the frequency is 400 Hz and the residence time is 2s, the removal efficiency of NO and NO_x is 81.0% or 44.8% respectively. NO_x removal efficiency can be significantly improved by the process of narrow pulse discharge reaction coupling with wet absorption, the average concentration of NO_x at the outlet is 43.9 mg/m³, and the average removal efficiency of NO_x is 64.1%, which is 19.8% higher than the efficiency of single narrow pulse discharge reaction, the narrow pulse discharge reactor has no obvious effect on the conversion of the original low concentration N₂O and CO in the municipal solid waste incineration flue gas, nor new N₂O and CO were produced. The research results of this paper have positive guiding significance for the industrial application of narrow pulse discharge reactor in the deep denitration of municipal solid waste incineration flue gas.