This work has dealt with the efficient degradation of styrene in a reactor system comprised of non-thermal plasma and Pd/ZSM-5 catalyst at room temperature. The problems regarding the individual plasma and catalytic processes such as poor low-temperature activity of the catalytic process and incomplete oxidation of the plasma process were complemented by the combination of both. The results demonstrated that the plasma-coupled Pd/ZSM-5 catalyst significantly enhanced both the styrene oxidation and the CO2 selectivity as compared with the plasma-alone case, greatly reducing the byproducts. The styrene degradation efficiency proportionally increased with increasing the specific input energy. Ozone formed by the plasma played an important role in the oxidation of styrene. The Pd/ZSM5 catalyst could be activated by the plasma, which greatly enhanced the performance for the styrene removal.