The invention relates to a secondary air gas-fired boiler 
combustor and a configuration method of secondary air, and belongs to the technical field of gas-fired boiler emission reduction. The technical aims that 
NOx emissions are reduced through a gas-fired boiler, and meanwhile the heat efficiency of the boiler is not reduced are achieved. The secondary air gas-fired boiler 
combustor is characterized in that an inner cavity of a 
hearth is sequentially divided into a main 
combustion area, a 
secondary air injection area and an after-
combustion area in the 
flue gas flowing direction starting from a gas 
combustor; the distance between the main 
combustion area and the gas combustor ranges from 0 m to 1 m, and 70%-95% of the 
air volume is supplied by the gas combustor; and the distance between the 
secondary air injection area and the gas combustor ranges from 1 m to 9 m, the furnace wall of the 
hearth is provided with a plurality of secondary air nozzles connected with a secondary air conveying pipeline, and 5%-30% of the 
air volume is supplied by the secondary air nozzles. The secondary air gas-fired boiler combustor has the beneficial effects that the secondary air nozzles are formed in the downstream portion of the gas combustor, the combustion temperature of the main combustion area is reduced, the reducibility 
atmosphere of the main combustion area is made, and generated thermal 
NOx and generated fuel 
NOx are restrained; and the secondary air guarantees that gas fuel is completely combusted, and the heat efficiency of the boiler is not reduced.