To characterize the splashing behavior under the impact of the top-blown gas jet in converter, in this paper a physical model is developed with the prototype of a 200 t converter in China. We captured the impact cavity morphology triggered by the top-blown gas jet of the oxygen lance, and found that the impact cavity shape gradually changed following the sequence of “disc” → “bowl” → “cone” with the increase in the gas flow, leading to the variation of the splashing modes. Moreover, the splashing inside and outside the converter was characterized quantitatively under the different top-blown gas jet conditions. The results showed that the splashing on the furnace inner wall concentrated at the region adjacent to the molten bath surface, implying severe flushing of the furnace lining of this region. The critical gas flow of splashing outside the converter is 32.3 Nm³·h⁻¹, corresponding to a gas flow of 39,000 Nm³·h⁻¹ in the prototype. In addition, the foaming slag can suppress the splashing during the smelting process. The statistics of the splashing flux provide a reference for maintaining the safety of the workers and the converter equipment.