A three-dimensional porous lead dioxide electrode (3D-PbO2) was developed by the template electrodeposition approach. Polystyrene microspheres were prepared by microemulsion polymerization, and then the polystyrene template was loaded on the PbO2 electrode by electrodeposition. Finally, a porous structure was formed by removing the template. Under these optimized conditions, the degradation of acyclovir could achieve complete removal, while the removal of COD was 29.59%. The electrochemical degradation process of acyclovir was consistent with the proposed primary reaction kinetics. The 3D-PbO2 electrode was comprehensively characterized using scanning electron microscopy S(EM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. The SEM analysis revealed the presence of well-defined porous structures on the electrode surface, while the XRD results indicated a reduction in electrode crystal sizes. Additionally, the XPS analysis demonstrated a higher proportion of reactive oxygen species on the 3D-PbO2 electrode. The electrochemical properties of the electrode were investigated using CV and EIS. The experimental findings demonstrate that the 3D-PbO2 electrode exhibits a higher oxygen evolution potential and lower charge transfer resistance than the conventional PbO2 electrode. This study presents a viable approach to enhance the electrochemical oxidation performance of lead dioxide.