Abstract Bi-doping PbO2 electrode, which is called Bi–PbO2 for short, modified with different concentrations of polyethylene glycol (PEG) was prepared by electrodeposition method in this paper. The microstructure and electrochemical properties of the different modified electrodes were investigated using scanning electron microscopy, X-ray diffraction, Mott–Schottky, electrochemical impedance spectroscopy and linear sweep voltammetry techniques. The results show that adulteration of PEG has a noticeable improvement in the morphology of Bi–PbO2 electrode which can greatly decrease its particle size and enlarge its active surface area. Phenol degradation experiments reveal that the modified electrodes have excellent electro-catalytic activity and stability, and the optimal adulterate concentration of PEG is 8gL−1. Electrochemical performance tests show that the modified electrodes exhibit more negative flatband potential (Efb), larger adsorption pseudo capacitance, lower adsorption resistance and higher oxygen evolution potential, and these characteristics promote the electro-catalytic activity of the Bi–PbO2 electrode. Finally, accelerated lifetime tests demonstrate that PEG modification can highly lengthen the service life of Bi–PbO2 electrode in its practical application.