Abstract: A new type of spray gun was placed at the wall of a hot metal ladle (relative to the outlet of slag removal). Before slag removal, high pressure N₂ was injected and floated, and slag on the ladle surface was pushed aside to the ladle outlet. The operation is positive to removing slag from the ladle, the efficiency improves, and the loss of hot metal and the time of slag removal decrease. A model in a proportion of 1:3.5 was made to simulate the hot metal ladle. Air was injected to blow slag. The simulation was operated with various parameters. At the same time, numerical simulation was made to testify the result. It is shown that when the submerged depth varies from 200 mm to 400 mm, the ratio of lack-slag area to sum area rises from 10% to 30%. When the flux of gas changes from 4 m³·h^-1 to 6 m³·h^-1, the ratio of lack-slag area to sum area increases from 30% to 37%. The increases of submerged depth and gas-blowing flux are positive to the quantity of slag removal. The result of water modelling is well accorded with the numerical simulation.