Nitrogen oxides in industrial flue gas are an important cause of environmental pollution. Non-thermal plasma technology is widely used to remove pollutants in flue gas, based on the oxidation of active particles. In this paper, a dielectric barrier discharge plasma generation system was designed and the oxidation of NO by non-thermal plasma was investigated, focusing on the effects of specific energy density (SED) and oxygen content. The results showed that when SED increased from 960 J/ L to 1920 J/L, the conversion efficiency of NO decreased. At the same time, the decrease of oxygen concentration promoted the conversion of NO. In combination with the oxidation catalyst, NO conversion could be dramatically promoted. A 500 m^3/h pilot-scale device was designed according to the laboratory results. The test was carried out in an industrial silicon submerged arc furnace. The results showed that NO could be completely converted with inlet NO volume fraction of 0~0.005%. The generated NO_2 was adsorbed on the surface of the catalytic material initially and gradually desorbed with the proceeding of the reaction. For inlet NO volume fraction of 0.005%~0.025%, the average outlet NO concentration was 0.001%(volume fraction). The above results confirmed the feasibility of NO conversion employing non-thermal plasma coupled with the catalyst.