The invention relates to an aluminum alloy T6 heat treatment furnace flue gas waste heat utilization device and method. The aluminum alloy T6 heat treatment furnace flue gas waste heat utilization device comprises a solid solution furnace, an aging furnace and a flue system of the aluminum alloy T6 heat treatment furnace; and the device is characterized in that high-temperature flue gas of the solid solution furnace is introduced into the aging furnace with lower temperature through a waste heat utilization pipeline, through monitoring of the furnace temperature and the flue gas temperature, aflue electric butterfly valve is controlled to supply the flue gas as needed, and the influence of low-temperature flue gas and excessive flue gas on the furnace temperature of the aging furnace is eliminated. According to the flue gas waste heat utilization system, effective recovery of flue gas waste heat can be realized, energy conservation and emission reduction are realized, and the heat treatment quality of a workpiece can be effectively ensured.