In order to develop clean and inexpensive fuels for iron ore sintering to alleviate the implementation of coal control and coal reduction policies in the iron and steel industry, and to focus on the national strategic needs of "Carbon Neutrality and Carbon Peaking", the semi-coke is used to instead of part of the breeze as sintering fuel; through the methods of optimizing mixing and particle size, the effects of different substitution ratios and different particle sizes of semi-coke on the quality and performance indexes of sinter are studied. The results show that, when the proportion of semi-coke replacing breeze is 60%, and the proportion of ≤0.5 mm grain level of semi-coke is 10%; the performance index of sinter is the best. At this time, the discharges of CO₂ and SO₂ in flue gas are decreased by 0.98% and 3.706×10^-3%, respectively, but the NO_x discharge is increased by 9.49×10^-4%. The analysis of mineral microstructure shows that controlling the proportion of ≤0.5 mm grain level of semi-coke can help improve the quality of sinter.