Abstract: Using numerical simulation method, the influences of bath depth, gas flow and oxygen lance inclination, as well as lance diameter on gas holdup, melt average velocity and turbulent kinetic energy are studied respectively. The results show that, when the bath depth is around 1.3~1.5 m, the gas-liquid phase in the bath is agitated strongly and the bigger bath gas rate is 17.5 %. The bath motion is in the better state. With the gas flow increasing, the bath gas rate, melt average velocity and average turbulent kinetic energy decrease firstly, and then increase. The optimal parameter is in the range of 0.6~0.7 kg/s. The bath gas rate increases first and then decreases as oxygen lance inclination increases, while the melt average velocity and average turbulent kinetic energy decrease first and then increase. The proper parameter is in the range of 20°~ 25°.When the lance diameter is in the range of 30~35 mm, there exist bigger values for bath gas rate and turbulent kinetic energy which are 13 % and 0.8 m²/s² respectively. At this moment, the bath motion is in the better state.