Abstract: The technology combining reactive distillation with one-stage extraction was proposed to replace the two-stage extractive distillation. The dimerization reactions and their Arrhenius equations were determined. The processes of thermal dimerization reaction and reactive distillation were simulated with Aspen Plus respectively. The results showed that the loss of isoprene decreased by 40.68％ by the reactive distillation process and the selectivity of cyclopentadiene dimerization increased. Alkynes entering extractive distillation decreased so that alkynes in isoprene product obtained later were lower than 50×10^－6 and cyclopentadiene was lower than 1×10^－6 by distillation after extractive distillation and stripping，and thus polymer-grade isoprene was obtained. The one-stage extraction technology has the advantages of short flow scheme，low loss of isoprene and low requirement for regenerating solvent.