The invention discloses a porous membrane cathode for a photoelectric-Fenton treating system, as well as a preparation technology of the porous member cathode. The preparation technology comprises the following steps: pretreating graphite powder to obtain a substance B, and treating the substance B through a KNO3 water solution, a nonylphenol polyoxyethylene ether water solution, ethanol, tertbutyl alcohol and polytetrafluoroethylene emulsion to obtain cream A; smearing the cream A on one side of a treated nickel screen, and extruding to obtain a substance E; preparing a solution C; preparing a cream B from the substance B, a KNO3 water solution, a nonylphenol polyoxyethylene ether water solution, ethyl ether, methanol, 2-ethylanthraquinone, the solution C and the polytetrafluoroethylene emulsion; and smearing the cream B on the other side of the substance E, and extruding, forging and cooling to obtain the porous membrane cathode for the photoelectric-Fenton treating system.