The design of the Korean traditional distiller ‘sojutgori’ was extracted as a digital sketch, and the internal fluid flow in the distillation process was tracked through computer simulation. Based on this, a new design was derived to improve distillation efficiency and its changes were researched. The ethanol particles vaporized inside the distiller were stagnated or their discharge was accelerated according to the magnitude and frequency of vortex. If the center is narrow and the fluid rotates, the vortex decreases or changes to a regular form. To effectively control the vortex, six simple models and two materialized models were designed and the optimal design was derived. When compared with the traditional distiller, the outlet fluid speed of the final design increased by 78% and the residence time dispersion of ethanol particles decreased by 39%. Furthermore, to suppress the temperature spread of fermented wash, a streamlined blade structure that can promote convection current was added. This structure had the effect of reducing the temperature spread of fermented wash by 57%. In addition, a reflux ring structure that can control the recondensed fermented wash caused by heat loss at the inner wall of the distiller was designed and applied. The reflux ring structure minimized the temperature change of the fermented wash and decreased temperature change by 23% compared to the condition without the reflux ring structure.