In view of the selective hydrogenation of benzene to cyclohexene in a series two-tank continuous hydrogenation reactor, the conversion rate of benzene and the selectivity values of cyclohexene in actual production are lower than the design value, the effects of Zn2+ concentration in mother liquor, Zn2+ concentration in catalyst and stirrer speed on the performance of Ru-Zn catalyst for benzene hydrogenation to cyclohexene were investigated. The results show that the selectivity of cyclohexene can be improved by increasing the concentration of Zn2+ in mother liquor to a certain extent; the selectivity of cyclohexene can be improved by increasing the concentration of Zn2+ in the catalyst, but the conversion rate of benzene decreased accordingly, and the yield of cyclohexene reaches the maximum when the speed of the stirrer is 120 r/min. By comparing the performances of the supported Ru-Zn catalyst and the unsupported Ru-Zn catalyst, the unsupported Ru-Zn catalyst has a higher yield of cyclohexene. The optimal conditions for selective hydrogenation of benzene to cyclohexene are the concentration of Zn2+ in mother liquor is 5%, the concentration of Zn2+ in catalyst is 2.0%, and the stirrer speed is 120 r/min.