Abstract: In order to investigate the impact of the parameters of seawater desulfurization process, such as exhausted air quantity, inlet SO₂ concentration and liquid to gas ratio, and the parameters of alkaline liquor desulfurization process, such as pH value of Circulating liquid, waste liquid discharge, liquid to gas ratio, on the efficiency of desulfurization tower, simulation of desulfurization process in the packing tower for W6X35 diesel engine is carried out by means of chemical process simulation software Aspen Plus V10. The parameters are optimized through the simulation. The simulations reveal that, for seawater desulfurization, the liquid to gas ratio is an important control parameter, that should be adjusted within the range of 3～7 L/Nm³ according to processing load and fuel sulfur content, while for alkaline liquor desulfurization, waste liquid discharge has the greatest impact on desulfurization efficiency, Na₂SO₃ crystallization from the saturated solution and waste liquid treatment load and should be adjusted within the range of 0.105～0.152 kg/kW·h, the lower end being preferable. pH value of circulating liquid and liquid to gas ratio affect the desulfurization efficiency and operation economy rather significantly and preferred values are 6.5 for pH value of circulating liquid and 3～4 L/Nm³ for liquid to gas ratio.