Biomass co-firing in coal-fired power plants has the advantages of low conversion cost,flexible peak shaving,and safe operation,which has a positive effect on carbon emission reduction and can realize the efficient utilization of biomass. At present,a large number of experiments and simulation studies have been carried out on the blending of sludge and other substances in coal-fired boilers,but there are few numerical simulation studies on the blending of distiller′s grains in coal-fired boilers. In order to study the influence of blending distiller′s grains in coal-fired boilers on the temperature field,component concentration field and NOx emission in the furnace,the mixed combustion of pulverized coal and distiller′s grains was simulated by numerical simulation and the vortex dissipation model in computational fluid dynamics software FLUENT. The results show that the simulation method is reliable. Under full load,the simulated outlet oxygen,carbon content of fly ash and NOx emission are in good agreement with the experimental results under the same conditions. The simulation results of 0,3%,6%,8% and 10% of the mass fraction of distiller′s grains show that the ignition distance near the nozzle of the burner is shortened,but the overall temperature field of the furnace does not change significantly. The concentration distribution of O2 in the furnace is not significantly affected by the blending of distiller′s grains,the concentration of H2O is increased near the burner nozzle due to the influence of distiller′s grains water content. Blending distiller′s grains have a significant impact on NOx emission,which is the result of the interaction of reducing atmosphere caused by the nitrogen content of blending fuel and the release of biomass volatiles.