Abstract: The gasification reactions of char have an important influence on combustion and pollutant formation under the condition of deep air-staging. In this paper,the influence of char gasification on the combustion and NO_xemission characteristics of pulverized coal under the condition of SR1 from 1.2 to 0.6 by the method of drop-tube furnace experiment and numerical calculation. Compared with the experimental data of the drop-tube furnace and the results of the traditional model and the improved model( considering char gasification),it can be seen that the traditional model has some defects in the prediction of reducing atmosphere of air-staged combustion,and the improved model is more consistent with the experimental results. The results of the experiment and the caculation of the improved model show that under the condition of deep air-staging,the main combustion zone is extremely anoxic,and the combustion process changes from the initial volatile ignition( R1 and R2) and incomplete char oxidation( R4) to the combustion state dominated by char gasification reaction( R5 and R6). At this time,a large amount of CO is generated,and the high concentration of CO_2 is consumed gradually until the end of reduction zone. With the addition of exhausted air,the oxygen content increases,CO is rapidly consumed( mainly R2),and CO_2 is gradually generated. The NO_xemission characteristics under the air classification condition are as follows: the NO_xconcentration near the burner is high; With the formation of reducing atmosphere,the NO_xlevel remains low after a certain degree of decline; And with the addition of burnout air,there is a certain degree of " rebound",which is caused by the rapid oxidation of some nitrogen intermediates that are not completely reduced after the addition of burnout air when the reduction zone is end.