Abstract: In order to improve the low utilization rate of desulfurizer in KR desulfurization process, four kinds of blade structures which were beneficial to industrial realization were designed to improve the mixing effect of KR desulfurization. The entrainment capacity and mixing effect of molten iron were analyzed by numerical simulation method, which was characterized by velocity field, turbulent kinetic energy, mixing time and desulphurizer distribution. By comparing the flow characteristics of molten iron with four kinds of blade structures, the influence of blade structure on the mixing effect of KR desulfurization was explored. The results show that under the action of impeller rotation, the formation rate of molten iron at the bottom of the impeller is not more than 0.6 m/s in the weak flow zone. Although the inclined blade impeller can enhance the entrainment capacity of molten iron, the improvement effect on the weak flow zone is limited. The influence of the blade number parameter on the weak current region is stronger than that of the blade inclination parameter. The three-blade propeller can effectively improve the hydrodynamic performance of the iron and reduce the volume of the weak current region. The inclined blade propeller has the advantage of local rapid mixing, while the straight blade propeller is more suitable for the overall mixing demand of the iron ladle. The molten iron mixing time of the straight four-blade impeller is the shortest, which is 49.48 s at the speed of 90 r/min, which is 2.8% and 2.7% shorter than that of the oblique four-blade impeller and the straight three-blade impeller, respectively. The inclined blade impeller is easy to cause the agglomeration of desulfurizer due to the strong vortex entrainment effect. The proportion of desulfurizer at the bottom of the straight four-blade impeller is about twice that of the inclined four-blade impeller, which is more conducive to the mixing of molten iron and desulfurizer, thus significantly improving the KR desulfurization mixing effect.