To solve the existing energy crisis and achieve continuous seawater electrolysis, it is necessary to design efficient electrocatalysts to deal with the problems of slow anodic oxygen evolution and chloride ion (Cl^-) corrosion. In this study, a unique nanostructural modified Ce-FeHPi/NF electrode was prepared by a one-step hydrothermal method on a nickel foam (NF) skeleton. The experimental results show that Ce doping regulates the surface morphology of FeHPi/NF, forming amorphous nanospheres, which not only enables the catalytic layer to grow into a compact nanostructure, but also greatly increases the active surface area of the electrode, significantly improving the electrocatalytic activity. In addition, the presence of phosphoric acid group can effectively repel Cl^- on surface of the electrode, which enhances its corrosion resistance, and stabilizes it in seawater for a long time. The 10%Ce-FeHPi/NF electrode in alkaline simulated seawater (1 mol·L^-1 KOH + 0.5 mol·L^-1 NaCl) electrolyte requires only a low overpotential of 296 mV to reach a current density of 100 mA·cm^-2. In 1 mol·L^-1 KOH + 1 mol·L^-1 NaCl, the 10%Ce-FeHPi/NF electrode runs stably for more than 130 h at a constant potential of 1.774 V (vs. RHE). Therefore, the modified nanostructured material prepared in this study can effectively improve the oxygen evolution activity of electrodes, and provide a new way for the development of seawater electrolytic anode catalytic materials.