The invention relates to a sintering waste heat and pure burning blast-furnace gas combined generating system, and belongs to the technical field of steel metallurgy waste heat utilization. The combined generating system comprises a sintering waste heat reclaiming system, a pure burning blast-furnace gas boiler, a steam turbine and a generator; the pure burning blast-furnace gas boiler is divided into an upper combustion system and a lower combustion system and adopts a cyclone burner, and the boiler is ensured to operate safely and stably by using an arrangement mode of front and back walls or tangential four corners; the low temperature and pressure or medium temperature and pressure vapor generated by the sintering waste heat replaces desuperheating water to enter an overheater of the pure burning blast-furnace gas boiler or directly enter a boiler barrel to generate the medium temperature and pressure or high temperature and pressure vapor for generating; and water for the sintering waste heat reclaiming system is supplied by a secondary coal economizer of the boiler. When the supply of the sintering waste heat system and the blast-furnace gas is enough, the lower combustion system is put into operation, and the system operates under higher load working conditions. The combined generating system has the advantages that the system can greatly improve the utilization efficiency of the reclaimed sintering waste heat, ensures the stable operation of the system, reduces the diffusion of the blast-furnace gas, and has good economic benefit and popularization and application values.