The invention discloses a system for co-processing N2O and VOC in caprolactam production waste gas. According to the flow direction of the waste gas, the system includes a gas storage device, a waterwashing device, a gas dilution device, a catalytic reaction device, a flue gas monitoring device, and a gas discharging device. The invention also discloses a method for co-processing the N2O and theVOC in the caprolactam production waste gas by using the system. The caprolactam production waste gas enters the water washing device from the gas storage device, after pretreatment is performed, thepretreated product enters the catalytic reaction device, a redox reaction is performed under the action of a catalyst, various indexes of the products are detected by the flue gas monitoring device, and discharge is performed through the gas discharging device. The method utilizes oxidability of the N2O in the caprolactam production waste gas for the first time to synergistically treat tert-butanol in the caprolactam production waste gas, the conversion rate of the N2O is 99.95-99.98%, the conversion rate of the tert-butanol is 99.96-99.99%, and the purpose of treating waste with waste is realized; and the system and the method are technological innovation in the field of energy conservation and environmental protection, and have economic, practical and industrial application prospects.