Abstract: In order to achieve a rapid and accurate selection for extractive distillation solvent, and to acquire 1,2,3-trimethylbenzene with high purity from solvent oil via extractive distillation, the UNIFAC model was used to calculate the relative volatility of 1,2,3-trimethylbenzene to indane (the mass ratio of 1,2,3-trimethylbenzene to indane is 4∶1) in five different solvents, acetophenone, di-2-octylhexyl phthalate(DOP), glycol, dimethyl sulfoxide（DMSO），sulfolane at 17.47 kPa. Meanwhile, the isobaric vapor-liquid equilibrium data of these five systems were measured. Deviations of the calculated values with the experimental values were all less than 6％. The results showed that sulfolane is a suitable extractive distillation solvent. Compared with other methods for selecting extractive distillation solvent，the combination of the UNIFAC model with experiments proposed in this paper has the advantages of rapidity, accuracy and high efficiency.