The utility model relates to an oxygen -enriched combustion system, wherein, this oxygen -enriched combustion system includes boiler (1) and coal pulverizer (2), the furnace of boiler entry (11) with coal pulverizer export (22) the intercommunication of coal pulverizer, furnace exit (12) of boiler with coal pulverizer entry (21) the intercommunication of coal pulverizer furnace exit with be provided with on the pipeline between the coal pulverizer entry be used for to the flue gas cooling device of at least partly moisture condensation in the boiler is supplied the notes oxygen device group of oxygen and is used for making the flue gas. In this technical scheme, set up flue gas cooling device on the pipeline between furnace exit and coal pulverizer entry, the hydrometeor that cooling action through this flue gas cooling device contains in with the flue gas forms the aqueous water to make it discharge from the pipeline between this furnace exit and the coal pulverizer entry, thereby can prevent that interior each pipeline to furnace and boiler system of moisture to re -enter the furnace in the flue gas from causing the harm.