In recent years, with the aggravating of environmental pollution, the purification of carbon monoxide is currently a subject of interest. The catalytic oxidation method is an effective way. Manganese oxide nanoparticles were prepared by emulsion self-assembly method and then, synthetic and commercial manganese oxide-supported gold nanoparticle catalysts were successfully synthesized by the deposition-precipitation (DP) method. The catalysts were characterized by XRD, Raman, BET, ICP and HRTEM. The activity of the oxide and oxide-supported gold nanoparticle catalysts were evaluated on the fixed bed microreactor and Au/MnOx had the highest activity. The intrinsic activity of Au/MnOx at 35 °C is 0.81 molCO·mol-1Au·min-1. Compared with O2, CO concentration has bigger effect on the reaction activity.