Abstract: To improve the degradation capability of the dielectric barrier discharge technology on benzene,using sulfate and ammonium persulphate as raw materials,β-MnO₂ are prepared by hydrothermal method,FeMnOx catalyst are prepared by impregnation method,and used to degrade the benzene in the simulated air combined with plasma.The effects of β-MnO₂ and FeMnOx on the different conditions was evaluated. The result indicates that the degradation ratio of benzene and the selectivity of carbon dioxide are improved when the plasma degradation and manganese dioxide catalytic degradation are simultaneously used,the degradation efficiency of benzene and the selectivity of carbon dioxide are both improved with the increasing of power,but decrease with the increasing of gas velocity.The degradation ratio of benzene increases to 73.4% and the selectivity of carbon dioxide grows up to 86.5%.