A process for preparing nano-Ag / zeolite film catalyst used to prepare phenylacetaldehyde from phenethyl alcohol includes such steps as preparing the zeolite film attached metal mesh by overlaying method, immersing it as cathode in the silver nitrate electrolyte, arranging silver electrode as anode in it, electrolyzing to deposit the Ag nanoparticles on said zeolite film, washing, Adding Ag2O or Zn (or Mn) oxide by impregnating method or dry mixing method, baking, and calcining.