Abstract: In order to research the sulfur fixation performance of steel slag in the coal-fired sulfur fixation process, the effect of single parameters such as calcium-sulfur ratio, air flow rate, furnace temperature, and furnace residence time on the sulfur fixation efficiency was studied. In addition, orthogonal experiments were constructed to assess the effect of each variable on the main and secondary order of sulfur fixation efficiency, and the ideal experiment design was identified. Utilizing XRF, the slagging features of the ash and the sulfur-fixing effect of the steel slag were analyzed.XRD was utilized to characterize the diffraction peaks of steel slag and sulfur fixation slag, which indicated the steel slag's capacity to fixate sulfur. SEM was used to describe the microscopic morphology of sulfur fixing ash, and the surface structure and microscopic morphology of steel slag before and after sulfur fixing were compared to evaluate the validity of other characterisation results. The results suggest that the slag has a good sulfur fixation capacity at 900 ℃, with a sulfur fixation efficiency of 63.17%, and that the sulfur fixation efficiency of the slag may reach 70.08% when 2% Na₂CO₃ is added.