The efficient and stable operation of waste incinerators and the reduction of NOx(nitrogen oxides) emissions are the currently challenges faced in the process of municipal solid waste(MSW) incineration. Taking a 500 t/ d waste incinerator as an object, theeffects of different air distribution schemes on the combustion process, flow field distribution and the optimal selective non-catalytic reduction (SNCR) process parameters were investigated for MSW mixed with high calorific value waste (ISW). The results show that the maximum temperature corresponding to the bed layer of different levels of primary air ratios remains basically unchanged. However, the maximum rate of volatilization analysis out increases, and the combustion of volatile and fixed carbon is advanced by increasing the air distribution in the first and second air chambers of the grate. A good secondary air injection angle can effectively organize the airflow in the furnace.Under condition 7, the phenomenon of high temperature sticking to the wall in the furnace is the lightest, and the distribution of flowlines is also more reasonable, so the secondary air angle setting in this working condition is the most reasonable. After SNCR reductant injection, NOx emissions are significantly reduced, and the denitrification efficiency is highest when the injection speed is 50 m/ s, up to33.96%. Therefore, it is recommended to use suitable air distribution and secondary air injection angles and to combine with SNCR technology for NOx reductionin actual operation.