A hybrid surface/packed-bed discharge (HSPBD) plasma reactor has been developed for plasma-catalytic degradation of benzene over different AgxCe1−x/γ-Al2O3 catalysts. The AgxCe1−x/γ-Al2O3 catalysts were combined with surface discharge plasma and packed-bed discharge plasma in inplasma catalysis (IPC) and post-plasma catalysis (PPC) configurations, respectively, to investigate the effect of catalysts packed into different plasma regions on discharge characteristics and determine consequent synergistic effects in the plasma-catalytic destruction reactions. In addition, the effect of active metal component ratio (Ag/Ce atomic ratio) on the activities of catalysts for benzene degradation was also investigated. The experimental results showed that the catalytic performance of AgxCe1−x/γ-Al2O3 catalysts for benzene was strongly dependent on catalyst location. Almost complete destruction of benzene was achieved when the catalysts is placed downstream the packed-bed discharge region, but the catalysts packed into the packed-bed discharge region showed better promotional effect in CO2 selectivity. The catalyst activities for the benzene degradation and CO2 selectivity decreased in the following order: Ag0.9Ce0.1/γ-Al2O3> Ag0.7Ce0.3/γ-Al2O3> Ag0.5Ce0.5/γ-Al2O3> Ag/γ-Al2O3> Ag0.3Ce0.7/γ-Al2O3> Ag0.1Ce0.9/γ-Al2O3. Furthermore, the ozone produced by the plasma is able to dissociate on the surface of AgxCe1−x/γ-Al2O3 catalyst, thereby creating peroxide surface groups which greatly improve the decomposition of benzene.