The development of mixed combustion of green ammonia and coal in coal-fired power plants is beneficial to the carbon reductionof thermal power towards the goal of carbon neutrality. The ignition characteristics of coal particle is the key factor affecting the flexible operation of the units in the process of gradually increasing the ammonia mixing ratio in the furnace with the technology of mixed combustion.Based on the path of blended combustion technology for ammonia and coal powder mixed feed,a new two-stage flat flame burner was usedto study the ignition characteristics of single particle coal powder during ammonia coal mixed combustion process. The ignition mode andignition delay time of the pulverized Zhundong coal particles under different operating conditions (ammonia volume fraction of the carrier gas and the ambient oxygen concentration) were obtained from the image analyses with the high-speed photography and the backlight method. It is found that the ignition process of particles is dominated by the heterogeneous ignition mode dominates at the absence ofammonia,while ammonia cofiring increases the proportion of coal particles undergoing homogeneous ignition. Meanwhile,with an increasein the ammonia cofiring ration,the proportion of fragmented coal particles during the devolatilization stage increases. At the same time,by constructing a one-dimensional transient coal powder ignition model containing ammonia combustion reaction,the influence of ammoniaon the ignition characteristics of coal powder particles can be well reproduced. The effect is relatively small under the central reducing atmosphere.When the central oxygen volume fraction is 0.1 or 0.2,the addition of ammonia significantly reduces the ignition delay time of asingle particle,mainly due to the ammonia flame increasing the heating rate of coal powder particles.