In our previous experimental study, we used a desulfurization method, i.e., coupled oxidation-extraction desulfurization. To develop a new insight into the industrial-scale desulfurization process by this method, a process simulation study is of great importance. In this work, the industrial scale of the coupled desulfurization processing of ultralow-sulfur diesel fuel (ULSD), wherein [C₁ pyr]H₂PO₄ is employed in the oxidative desulfurization process and dimethylformamide (DMF) is employed in the extractive desulfurization process, has been examined through the Aspen Plus simulation. Sensitivity of various operating conditions, i.e., ionic liquid (IL)-to-oil ratio, DMF-to-oil ratio, and operating temperature and pressure, has been analyzed. Subsequently, the economical comparison of the proposed process and hydrodesulfurization (HDS) is compared synthetically. It is observed that the coupled desulfurization method can effectively remove the S-compounds from the diesel fuel to meet the requirement of stringent legislation of <10 ppm. The main objectives of this work are (i) to propose and design an industrial-scale process of the coupled oxidation-extraction desulfurization of diesel, (ii) to obtain the optimal operating conditions, thus enabling the simulation and optimization of this desulfurization process, and (iii) to verify the experimental results and evaluate the feasibility to scale up this technology. To the best of our knowledge, it is the first time to design an industrial-scale process for the coupled oxidation-extraction desulfurization of diesel fuel.