In recent years, as a carbon-free, hydrogen-rich fuel, ammonia is mostly used as a carbon-free fuel for internal combustion engines, gas turbines and other industrial applications. Ammonia/coal co-firing has also attracted a lot of attention in order to reduce CO2 emissions from coal-fired power stations. The methods for reducing carbon emissions from existing coal-fired power plant boilers were introduced, and the latest progress in ammonia/coal co-firing research was briefly described, and the potential problems in the ammonia/coal co-firing combustion process were analyzed, and the combustion characteristics and pollutant emission rules of ammonia/coal co-firing were revealed. In view of the combustion characteristics of ammonia in coal-fired boilers and the high NOx emission characteristics in the process of ammonia/coal co-firing, a test with 0-100% ammonia co-firing ratio was realized in a combustion furnace, and air-staged combustion technology was applied to ammonia/coal co-firing. The influence of different ammonia co-firing ratios and air-staged techniques (combustion ambient temperature,ammonia addition position) on ammonia/coal co-firing combustion products was examined further. The coal-fired boiler′s strong preheating conditions and high combustion ambient temperature in the furnace promote increase ammonia combustion. As a result, ammonia′s weak combustion properties will not be a significant barrier to ammonia/coal co-firing in coal-fired boilers. NOx emission concentration can be greatly reduced by adjusting the co-firing approach and modifying the air-staged combustion strategies. The length of the reduction zone can be extended by delaying the addition position of the burnout air, which is conductive to the selective non-catalytic reduction reaction between NH3 and NO in the reduction zone and the heterogeneous and homogeneous reduction reaction between coal pyrolysis products (volatile and char) and NO, effectively reducing NOx emissions. With a medium and high burnout air addition position and a burnout air ratio of 30% or more of the total air volume, the NOx emission concentration may be regulated at a level comparable to that of coal air-staged combustion if the ammonia co-firing ratio is managed at 20%-30% (calorific value). The peak concentration of H2S in the reduction zone of ammonia/coal co-firing lowers with increasing ammonia co-firing ratio under air-staged combustion circumstances, which may have a moderating trend on the corrosion of water-cooled wall pipes. Ammonia/coal co-firing will also considerably increase the gasification reaction of CO2/H2O and coal char in the reduction zone under air-staged combustion circumstances, resulting in the creation of huge volumes of CO. The utilization of ammonia/coal co-firing technology is a very potential technological advancement path toward achieving low carbon and low nitrogen emissions in coal-fired power plants.