The invention provides a method for re-circulating 
combustion of 
flue gas of a 
pulverized coal fired boiler, belongs to a method for circulating 
combustion of 
oxygen gas (O2) and 
carbon dioxide (CO2) of pulverized 
coal, and aims to solve the problems of low heat efficiency and poor burn-out property existing in the conventional 
combustion method. The method comprises the steps of: 1,igniting and combusting: conveying the pulverized 
coal to a furnace 
hearth by using the circulation 
flue gas, and simultaneously conveying O2 to the furnace 
hearth for ignition; 2, circulating the 
flue gas: dividing the high-temperature 
flue gas generated by combustion into two parts, and performing cooling, dust removal and desulfurization compression on the first part to obtain liquid CO2; dividing the second part into two paths, conveying the first path to an entrance of the furnace 
hearth by using a high-temperature circulation fan, and mixing the first path of the 
flue gas and O2; and performing cooling, dust removal and desulfurization on the second path, and conveying the second path carrying the pulverized 
coal to the furnace hearth by using a cold circulation fan. The method has the advantages of adjusting the 
steam temperature of the boiler by using the high-temperature 
flue gas, enhancing 
convective heat transfer, increasing the 
steam temperature of the boiler, improving the heat efficiency of the boiler and the denitration rate, increasing the CO2 content after the high-temperature flue gas is cooled, reducing emission load of 
NOx, lowering CO2 capturing and collecting cost, and meeting the national 
energy conservation and 
environmental protection standard.