The flue gas characteristics of cement kiln and the influence of SCR denitration system on cement kiln and waste heat power generation system were analyzed. In view of the difficulties in implementing SCR denitration, the technical route of "high temperature and high dust" SCR denitration process was determined to achieve ultra-low emission of nitrogen oxides at the kiln tail. Using "high temperature and high dust" SCR denitration system process scheme, nitrogen oxide emission concentration can be reduced from 300mg/Nm³ to 45mg/Nm³, to meet the requirements of ultra-low emission, ammonia escape concentration <5mg/Nm³, tons of clinker production cost is expected to increase 4.25 yuan, the total power generation of waste heat power generation system is expected to reduce 0.67%.