In order to reveal the effect of stainless steel pickling sludge on sintering performance and flue gas composition, under the premise of basic performance analysis of pickling sludge, the sintering cup test with pickling sludge was first carried out to grasp the change trend of junction performance,and drum strength, mineral phase and flue gas composition of sinter were analyzed. The results show that the dosage of pickling sludge increases,and the sintering utilization coefficient and yield show a downward trend. When the sludge content was 5%,the sinter strength decreased by 4.01%,and the SO₂ content of flue gas component increased by 5.79 times. CaF₂, CaO and SiO₂ form cuspidine, which has a great influence on the sintering strength, while CaSO₄ decomposes and escapes a large amount of SO₂ under the weak oxidation atmosphere of the sintering process. On this basis, the industrial test of using pickling sludge was carried out, and the results showed that the proportion of pickling sludge in the sintered mixture should not exceed 1%.