N-doped Ce0.2Zr0.8O2 catalysts for NO oxidation were successfully fabricated via NH3 treatment at high temperature, and the N doping amount could be controlled via adjusting the conditions of various NH3 concentrations and treatment times. The optimal 10N700-5 catalyst revealed the sensational oxidation efficiency at low temperature, which surpassed 50% at 180 degrees C and reached up to 82.82% at 270 degrees C. The excellent activity was ascribed to the numerous generations of O-2(-) and the accompanied vast formation of Cr6+, caused by N doping. N atoms were doped in Ce0.2Zr0.8O2 in the structure of Ce-O-N-O-Zr via the O-N-O bond between N and O. The analysis of affecting factors elucidated that cation ratios played a more significant role than the Brunauer-Emmett-Teller surface area, and Cr6+ ratios acted mostly. Additionally, the conceivable promotion mechanism by N doping for NO oxidation was examined via in situ DRIFTS. This work propelled denitration with the selective catalytic oxidation technique for industrial application and lent a novel perspective for the design of catalysts with satisfied oxidation efficiency at low temperature.