Abstract: During the industrial-scale argon P-ESR process, the accumulation of sulfur content removed from steel in melt slag will affect the efficiency of desulfurization reaction, causing a non-uniformity of sulfur content in the remelted ingot. Currently, research on electroslag desulfurization has been mainly conducted at a relatively small experimental scale, whose kinetic conditions is significantly different from the large-scale one so that its relevant research findings have its limitations on industrial applications. Therefore, this study established a desulfurization reaction model for industrial-scale electroslag remelting process. Its calculation results were basically consistent with the experimental ones, verified by a 3 t P-ESR experiment. The research results showed that reducing the initial sulfur content in the electrode and slag, increasing the slag volume and the sulfur capacity, and lowering the electrode descent speed are all conducive to improving the desulfurization ratio. A simplified formula of the model based on these research findings has been derived, which can be directly used to approximately calculate the sulfur content at different mass positions within the remelted ingot.