The invention discloses a device and a method for removing nitric oxides in adipic acid tail gas. The device comprises a reactor, an adipic acid tail gas discharge valve, a heater and a gas mixer, wherein a removal front sampling point and a removal front online concentration analyzer are arranged between the adipic acid tail gas discharge valve and the heater; a feeding thermometer is arranged between the heater and the gas mixer; the inlet of the gas mixer is connected with a gaseous ammonia pipeline and a low-pressure nitrogen gas replacement pipeline; a low-pressure nitrogen gas discharge valve is arranged on the low-pressure nitrogen gas replacement pipeline; a reactor inlet main valve and a reactor inlet bypass valve are arranged between the gas mixer and the reactor; a removal rear sampling point and a removal rear online concentration analyzer, a discharge pipeline valve and a reactor outlet main valve are arranged on the reactor outlet pipeline; an inlet-outlet differential pressure gauge and three thermometers are arranged on the reactor. According to the device, a catalyst can stably operate for a long time under a high-temperature acidic environment, so that corresponding reaction activity of the catalyst is kept, and a nitric oxide removal rate is higher than 95%.