This paper investigated the catalytic reduction reaction of NO by CO over Cu Catalyst with Chemical simulation software Chemkin. And it determined the major step of reduction reaction through the analysis of the surface coverage and reaction sensitivity over the catalyst surface. Then we carried on the experimental study of using blast furnace gas to remove NO of sintering flue gas through laboratory Simulation prepared gas. And we investigated the relationship between temperature and Denitration efficiency. The simulation results show that NO participated the reduction reaction as NO* and (NO)2* which are absorbed by the copper-based catalyst. CO covered almost the whole surface of the catalyst in the form of pioneer chemical adsorption when the reaction temperature is lower than 200℃ and almost no reduction reaction exist at the low-temperature. As the temperature getting higher, the coverage rate of CO* reduced, and the coverage rate of NO* and N* increased gradually and the conversion rate of reduction reaction increased gradually. The simulation results are consistent with the experimental results when the reaction temperature is between 200ï½Ãƒâ€šÃ‚ž450℃.