Non-thermal plasma (NTP) was produced in a dielectric barrier discharge reactor for degradation of acetaldehyde and benzene, respectively. The effect of volatile organic compounds (VOCs) chemical structure on the reaction was investigated. In addition, acetaldehyde was removed in different background gas. The results showed that, no matter in nitrogen, air or oxygen, NTP technology always exhibited high acetaldehyde removal efficiency at ambient temperature. However, it also caused some toxicity by-product such as NOx and ozone. Meanwhile, some intermediates such as acetic acid, amine and nitromethane were formed and resulted in low carbon dioxide selectivity. To solve above problems, Co–OMS-2 catalysts were synthesized and combined with plasma. It was found that, the introduction of catalysts improved VOCs removal efficiency and inhibited by-product formation of plasma significantly. The plasma-catalysis system was operated in a recycling experiment to investigate its stability. The acetaldehyde removal efficiency can be kept at 100 % in the whole process. However, slight deactivation in ozone control was observed at the later stage of the experiment, which may be ascribed to deposition of VOCs on the catalysts surface and reduction of catalysts surface area.