Ag@AgCl/CeO2 was prepared by soft template method assisted by microwave, sedimentation and photoreduction. The structure, morphology and composition of the prepared catalysts were investigated by XRD、SEM、EDS、TEM、N2-Adsorption desorption and UV-Vis DRS. Meanwhile, a photo-CWPO (Catalytic wet peroxide oxidation) system was established. The catalytic degradation of acrylonitrile wastewater by Ag@AgCl/CeO2 under UV-Vis irradiation was studied. The results showed that the Ag@AgCl/CeO2 prepared has ordered mesoporous structure, specific surface area was 422.8m2/g and the band gap was 2.9eV with strong absorption in visible light region. In the photo-CWPO system, when the concentration of acrylonitrile wastewater was 500mg / L, the dosage of catalyst was 200mg, the amount of H2O2 (30%) was 8ml, and the reaction time was 60min, COD removal rate can reach more than 90%, and it has high stability. The main role of the degradation process of acrylonitrile wastewater is the ?OH generated by the catalysis of Ag@AgCl/CeO2.