Abstract: With the increasingly strict requirements of environmental protection,in order to reduce the NOxemission of CFB units,it is necessary to accurately estimate the NOxconcentration generated in the furnace and apply it to the control. For this,it is necessary to establish an accurate and practical mechanism control model. At the same time,it is necessary to comprehensively consider the optimization control to reduce nitrogen oxide and SNCR generated in the furnace combustion,and the comprehensive control of nitrogen oxide inside and outside the furnace should be optimized by using this model.Based on the analysis of the formation mechanism of nitrogen oxides,the CO concentration prediction model at the furnace outlet was established with fuel NOxproduced by CFB boiler combustion as the main body,the method of mathematical modeling and simulation,and coal feed,air flow,etc. used as model inputs. Based on this model,the prediction model of the NOxconcentration at the furnace outlet could be established by using the model as the input of the burning coal model.The above method was used to establish a prediction model of CO concentration at furnace outlet,and the parameters of the model were obtained and simulated based on the actual operating data,and the furnace combustion control was not well coordinated with SNCR denitration,which led to the problem of high levels of nitrogen oxide emissions. Based on the established prediction model of NOxconcentration at furnace outlet,a comprehensive control technology route for nitrogen oxides inside and outside the furnace was proposed,and a primary and secondary air volume optimization and SNCR optimization control ideas were designed based on the NOxconcentration prediction model.The simulation proves that the established model has good accuracy,meets the accuracy requirements of the actual control system,and has a certain predictive effect. The design of the integrated nitrogen oxide control technology route and optimized control ideas inside and outside the furnace can provide a reference for the low-emission control of nitrogen oxides in circulating fluidized bed units.