The utility model discloses a nitrogen oxide's removing device in adipic acid tail gas, including diluting unit, a react unit and the 2nd react unit, dilute the unit and include that the vapour and liquid separator, the compressed air that connect in order on the management way dilute container and first concentration on line analyzer, a react unit includes feed preheater, heating device, reaction unit a gentleness / gas heat exchanger of connecting in order on the management way, the 2nd react unit includes hybrid system, second concentration on line analyzer, the 2nd reaction unit, third concentration on line analyzer and the heat reclaim unit who connects in order on the management way. All be provided with a plurality of bayonet thermometers at a reaction unit and the 2nd reaction unit top, every thermometer is divided into a plurality of points for measuring temperature at catalyst bed top -down. The utility model discloses can make catalyst steady operation under long -term high temperature, acid environment, keep its reactivity, make nitrous oxide desorption rate reach more than 98%, nitrogen dioxide and nitric oxide desorption rate reach more than 95%.