Abstract: FLUENT numerical simulation software was used to simulate the process of ladle bottom blowing argon in ladle furnace (LF) refining furnace smelting process. The causes of water leakage of LF refining furnace water-cooled furnace cover were analyzed from the aspects of bottom blowing argon flow rate, slag basicity, slag layer thickness and actual furnace cover structure, and the rectification measures were put forward according to the calculation results and field practice. The results showed that the areas prone to leakage were near the bottom blowing element and away from the bottom blowing element. The large argon flow rate obviously caused the molten steel level to fluctuate violently, and it was easy to produce two higher bulges. When the basicity of slag layer was low, the force between liquid steel and slag layer decreased, and the liquid level fluctuated violently. When the thickness of slag layer was small, it could not cover the surface of liquid steel well, and liquid steel fluctuated greatly.