A variable-velocity stirring method is proposed to improve the desulfurization efficiency of high-sulfur hot metal for KR desulphurization process. The mixing behavior of desulfurizer and high-sulfur hot metal under the variable-velocity stirring method is investigated using the Euler-granular model. The particle volume fraction, mixing time and power consumption are discussed to illustrate the entrainment and dispersion of desulfurizer. The results show that the flow field of hot metal and the entrainment and dispersion of desulfurizer are improved obviously under the variable-velocity stirring method. The particle volume fraction distribution is uniform and the mixing time is short under the stirring mode of 90–50 rpm for 8 s switch with the moderate power consumption and torque. The stirring mode of 90–50 rpm for 8 s switch is recommended to adopted within the present system, which can optimize the entrainment and dispersion of desulfurizer in the bath.