The invention discloses a method for leading flue gas out of a sintering flue gas waste heat utilization system without using an induced draft fan and belongs to the technical field of sintering machine flue gas waste heat utilization technology in steel industry. Flue gas on the tail part of a sintering machine enters a waste heat boiler through a tail air box and a flue gas branch pipe to exchange heat with a working medium; after the flue gas exchanges heat with the working medium, low-temperature flue gas enters a non-desulfurated smoke collecting header or a main smoke collecting header of a sintering system through a waste heat boiler flue passage arranged at one end of the waste heat boiler, and is led out and emptied after dust in the low-temperature flue gas is removed by a main exhaust fan in the non-desulfurated smoke collecting header or the main smoke collecting header. Equipment cost as well as running and maintenance costs increased due to the arrangement of an induced draft fan on the tail part of the waste heat boiler in a conventional sintering waste heat utilization system are saved and potential safety hazard to the system caused by running the induced draft fan in a severe environment is eliminated.