The invention belongs to the technical field of electro-chemicals, and relates to a proton exchange membrane water electrolysis ozone/oxygen generation device with a self-purifying function. An ion exchanger is serially connected in a cathode chamber and cathode water tank circulating loop; ion exchange resins are filled in a pure water tank for further purifying reflux water of a cathode water tank and fed raw material water; and the purified water is fed to the cathode water tank. The device can effectively exchange metal ions migrated to the cathode chamber through a proton exchange membrane and fed in the water of the cathode water tank by the cathode chamber, reduces the electric conductivity of the water to reduce the working voltage of an electrolysis tank, and largely prolongs the generator operation life.