In order to study the stirring effect of combined blowing on liquid steel of the 100 t ladle in Chengde steel. The results show that, liquid steel velocity, turbulent kinetic energy, impact area increase with the side flow rate rises, the dead pool decreased gradually, the stirring ability of gas on the weld pool increases. Increase the side air-blowing quantity has effect on the stirring of ladle slag layer, and it promotes the dephosphorization ability of molten steel.