Abstract: With the environmental policies being strict,the NO_x of conventional thermal power units can reach the level of less than 50 mg/m3 after combustion denitrification in furnace and post-combustion denitrification in flue through the transformation of ultra-low nitrogen emission.With the continuous development of low NO_x combustion technology,the ultra-low NO_x combustion technology of pulverized coal pyrolysis and gasification coupled with combustion has attracted more attention in the industry.The main idea of this technology is to introduce hot thermal source to heat up the pulverized coal air/fuel stream with ultra-low stoichiometric ratio in the pre-combustion chamber.The pulverized coal first fast releases volatile matter and partly combusts in the pre-combustion chamber.The gas phase products and high temperature semi-coke leave pre-combustion chamber and are transferred to the furnace through the burner for low NO_x combustion. Compared with traditional post-combustion denitrification method such as SCR and SNCR,this technology directly reduces nitrogen in the furnace combustion process by burning high-temperature semi-coke,which has greater technical advantages and economic potential. The pre-combustion source is the key step to produce gas phase products and high temperature semi-coke.According to different pre-combustion sources,this paper introduced these pulverized coal pre-combustion technologies,the natural gas heating pulverized coal pre-combustion,circulating fluidized bed heating pulverized coal pre-combustion,plasma ignition pre-combustion chamber,induction-heating ignition pre-combustion chamber and traditional pre-combustion chamber burners,etc.The progress and application of those technologies were analyzed to provide references for relevant technical staff.