The ladle bottom argon blowing process has an important influence on the refining liquid steel. The effects of diameters, insertion depth of immersed cylinder and bottom gas flow rate on the flow state of liquid steel and the amplitude of liquid steel surface are numerically simulated for 150t ladle. The results show that the slag entrapment of liquid steel surface can be confined by changing the diameters and insertion depths of immersed cylinder. The effects of gas flow rate, diameter and insertion depth with immersed cylinder on the flow of molten steel in the ladle were analyzed.