Abstract: The technological process for the separation of methylcyclopentane from raffinate oil was studied. Simulated by Aspen Plus software，the optimum design parameters，operating condition，heat duty of condenser and heater were obtained for common distillation. The separation of methylcyclopentane with methanol as entrainer in azeotropic distillation was also simulated. Meanwhile，the optimum design and operating condition of the azeotropic distillation column for methylcyclopentane were obtained.