Abstract: A 1∶3 model was established for a 120 t ladle in a steel mill, and the effects of nozzle position and gas flow rate on ladle flow field and slag interface behavior were analyzed by water physical simulation method. The results show that the larger the gas flow rate is, the larger the slag depth and slag hole area are. For double-hole 120° arrangement of bottom blowing method, the slag hole area is smallest, because two gas columns will offset and influence each other at the angle of 120°, the force on the interface of steel slag is least. The reasonable bottom blowing parameters for ladle argon blowing are as follows: double-hole nozzle 120°, gas flow 300 L/min.