Abstract: The preparation process of cyclohexene is affected greatly by catalyst and reaction temperature. The synthesis of cyclohexene is usually catalyzed by oil of vitriol or phosphoric acid in the textbook of experiments. Although this way is very classical,the production rate is relatively low. At the same time,the causticity of oil of vitriol is too strong,with seriously carbonized,which somewhat handicaps the manipulation. A new method of preparing cyclohexene with SO42-/NaHSO4/C as catalyst was discussed. The result shows that the catalyst is excellent catalyst for preparing cyclohexene by dehydration of cyclohexanol. It also has high yield and the catalyst can be used repeatedly with non-pollution.