High efficiency separation of benzene/cyclohexene azeotropic system at atmospheric pressure is the focus of current research. Extractive distillation is considered to be the most promising method for separation azeotropes. Therefore, it is necessary to screen suitable extractant for extractive distillation. The deep eutectic solvents (DES) formed by the combination of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) has a good application prospect in the separation of aromatic/nonaromatic azeotropes. In order to explore the influence of HBA and HBD on the separation performance of benzene/cyclohexene azeotropic system, the three kinds of DES were investigated in this work. The three kinds of DES consisted of HBA [tetrabutylammonium bromide (TBAB), choline chloride (ChCl)] and HBD [ethylene glycol (EG), levulinic acid (LA)] with the mole ratio of 1:2, which were marked as TBAB:EG (1:2), TBAB:LA (1:2), and ChCl:LA (1:2), respectively. The corresponding isobaric vapor-liquid equilibrium (VLE) of cyclohexene-benzene-DES were experimentally determined. The effect of HBA and HBD on separation performance were discussed systematically. By correlating the VLE data with the nonrandom two-liquid (NRTL) model, the binary parameters were fitted. The results showed that the separation performance of the three DES follows the order ChCl:LA (1:2)>TBAB:LA (1:2)>TBAB:EG (1:2). It was indicated that choosing HBA which had the lower steric hindrance effect and HBD which had the weaker polar bond were conducive to form an efficient extractant for benzene/cyclohexene azeotropic system separation. Subsequently, the extractive distillation process used ChCl:LA (1:2) as extractant were designed with Aspen Plus V7 to evaluate the separation energy consumption. For comparison, N,N-dimethylacetamide (DMAC) which is a traditional extractant was evaluated in the same condition. The process simulation results showed that using ChCl:LA (1:2) as extractant, the molar reflux ratio decreased from 3.8 to 0.30 and the total reboiler heat duty reduced 16.57%, compared with those of DMAC used as extractant.