The impeller blade structures are developed to maximize reagent utilization in the desulfurization process of molten iron by Kambara Reactor stirring method. Compared the flow structure and mixing effect of four impeller systems by numerical simulation. The distribution and motion behavior of desulfurizer particles are further discussed. In addition, the effect of rotation speed on mixing ability is illuminated. The results show that changing the central structure of the traditional impeller can effectively improve the flow field, changing the width of the asymmetrical impeller blades can enhance the involvement ability, and setting the downward angle on the basis of changing the width of asymmetrical impeller blades can obviously improve the mixing effect in the region under the impeller. The recommended rotation speed is 80 rpm, under actual operation conditions, since it may cause the overflow of molten iron when the rotation speed exceeds 80 rpm.