Abstract: By using chemical process simulation software Aspen Plus, the extractive distillation separation process for isobutanol-ethanol-water three-element system is simulated and optimized when glycerol is the extractant. The effects of reflux ratio, number of stage, feed position, location and amount of extractant on the process of distillation separation are investigated. The simulation results show that when the amount of raw material is 15 t/h, the content of isobutanol is 5 wt%, the content of ethanol is 9 wt%, and the water content is 86 wt%, the separation effect is satisfactory: isobutanol content in water is less than 20×10^-6, ethanol is less than 10×10^-6 and isobutanol product concentration is 98 wt%, and ethanol product concentration is 99 wt%. The effective recovery of isobutanol and ethanol and the standard discharge of organic wastewater are realized. The simulation and optimization results provide a reliable basis and reference for the industrial separation process of isobutanol-ethanol-water three element system and the transformation of energy saving and emission reduction.