The bio-electron-Fenton system integrates microbial fuel cell and Fenton process into a single system to destroy the organic and bio-refractory contaminants in wastewater. Its performance is closely dependent on the sufficient electron supplement by the oxidation process in anode chamber and the reduction process in cathode chamber. This article presents a novel cathode of a bio-electron-Fenton system which can simultaneously achieve good electron supplement and the wastewater treatment in cathode chamber. The cathode consists of indium-tin-oxide conductive glass on which layers of graphene-poly(vinyl alcohol) composite are sprayed by electrospinning. The material characterization is verified by Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The voltage, current, and power density of the system are verified by cyclic voltammetry. The wastewater treatment is verified by dye decolorization. With the addition ratio of 4 wt% graphene, the system achieves the optimal power density of 74.1 mW/m 2 , open-circuit voltage of 0.42 V, and the decolorization of reactive black 5 of 60.25%. By constant-resistance discharge testing within three-cycle, the system can stably supply a maximum voltage of 0.41 V or above. Hence, the proposed electrospun graphene-poly(vinyl alcohol) composite cathode electrode can not only improve the power-supply efficiency but also enhance the efficiency of wastewater treatment.