Water modeling is employed to study the bottom-argon blowing in a 70 t LF ladle with a scale of 1∶3. By taking construction features and technological rationality into consideration, nine alternative plugs located at three different radial directions are designed to investigate the effects of argon flow rate, location of the plug, plug number on mixing phenomenon. The results show that the mixing time decreases evidently with increasing argon flow rate within the range of small flow rates. When the flow rate reaches 400 L/min or more, the mixing time becomes to decrease slowly; increasing the number of plug from one to two shows less contribution to the performance of mixing at the same flow rate; and the case reaches the relatively best performance with the plug moves from 0.55R to 0.67R at the original direction.