A numerical simulation with finite element software was conducted basing on 470mm×350mm bloom during continuous casting with electromagnetic stirring .In the process of numerical simulation, the influence of EMS current and frequency on distribution of magnetic induction and electromagnetic force was considered. The comparison show that the calculated results conform basically with the experimental data. The distribution of electromagnetic force is circular in horizontal direction. At the same current, magnetic induction decrease with the frequency. Along the direction of mold, electromagnetic force increase with the frequency. With the increase of frequency,the largest increase in the amount of electromagnetic force decrease. At the same frequency, magnetic induction and electromagnetic force increase with the current. Considered the results of numerical simulation, the optimized EMS parameters are the stirring current of 550A and the stirring frequency of 2Hz.The flow field also was researched preliminary.