The invention discloses a system and method for producing high-temperature high-pressure steam and flue gas on the basis of an oxygen-enriched boiler, and belongs to the technical field of thick oil production. An air separation system is connected with the oxygen-enriched boiler, and is connected with a mixing and temperature adjusting chamber through a compressed nitrogen conveying pipeline, the oxygen-enriched boiler is connected with a steam and flue gas mixing injection system through a saturated steam conveying pipeline, the oxygen-enriched boiler is connected with a flue gas purification and pressurization system, and the flue gas purification and pressurization system is connected with the mixing and temperature adjusting chamber; oxygen and nitrogen are separated by the air separation system, wherein the oxygen and part of air are mixed to form oxygen-enriched air, and the oxygen-enriched air is fed into the oxygen-enriched boiler to react with fuel; flue gas generated by the oxygen-enriched boiler is purified and pressurized through the flue gas purification and pressurization system, the purified and pressurized flue gas is fed into the mixing and temperature adjusting chamber, mixing and temperature adjustment are carried out on the purified and pressurized flue gas and pressurized nitrogen fed by the air separation system through a pressurized nitrogen conveying pipeline, and finally, mixed gas is fed into the steam and flue gas mixing injection system; saturated steam generated by the oxygen-enriched boiler is led out of the saturated steam conveying pipeline to the steam and flue gas mixing injection system. According to the system and method for producing the high-temperature high-pressure steam and flue gas on the basis of the oxygen-enriched boiler, thick oil production efficiency is improved.