Background: Nitrogen oxides are an extremely harmful air pollutant, the chief culprit in the formation of photochemical smog and acid rain, and one of the causes of smog weather known as the "gentle killer" and "fierce killer". With the rapid development of social economy, science and technology and industry, its emissions have increased sharply. The cement industry is the third largest emitter of nitrogen oxides, second only to coal-fired power plants and automobile exhaust. In order to protect the environment on which human beings rely for survival, relevant standards have been formulated at home and abroad for the emission of nitrogen oxides in the cement industry, which are controlled in the form of law, and are constantly revised and become more and more strict. The limits of nitrogen oxide emission concentrations in advanced foreign countries have been tightened to below 200mg/Nm2. Our country's newly revised GB4915 -2013 "Cement Industry Air Pollutants Emission Standard" has been stipulated as 400mg/Nm2. It should be said that this is currently the most stringent environmental protection standard in the world, because my country has not yet burned alternative fuels to reach 100%. cement production line. However, some special areas in my country have required nitrogen oxide emission concentrations to reach a standard below 200mg/Nm2, such as Beijing City and Zhejiang Province. However, the denitrification system using the SNCR method is no longer able to meet the standards, and the SCR method must be used for flue gas denitrification to meet the requirements of these stricter standards.  Introduction to achievement: A selective catalytic reduction (SCR) flue gas denitrification technology with independent intellectual property rights has been developed. The traditional artificial one-dimensional design method is replaced by a multi-dimensional design that actively utilizes uneven utilization, which effectively solves the problem of excessive ammonia gas as the reducing agent in some reaction areas and insufficient ammonia nitrogen reaction in some reaction areas, and achieves the realization of large non-uniform flow fields. Precise matching of ammonia nitrogen concentration in each reaction area. A 2×600MW denitrification demonstration project has been built, filling a domestic gap, significantly reducing investment and operating costs, and shortening the construction period.