Abstract: The application of rotating magnetic filed on metallurgical reactor with an argon bottom injecting was proposed. The model of gas-liquid two phase flow behavior with the argon gas bottom injecting and the rotating magnetic field was established. The effect of nozzle position and magnetic field density on flow structure and gas bubble behavior of reactor was considered. The results showed that if there is only gas stirring, the shape of gas plume is the inverted cone. When the gas stirring and the rotating magnetic field are applied together, the shape of gas plume becomes the spiral. The simulation results showed a good agreement with the experiment observation. If the distance between reactor center and nozzle position and the magnetic density increase, the channel length which gas bubbles float to the free surface is prolonged in the linear and exponential form, respectively.