Abstract: Anion exchange membrane water electrolysis （AEMWE） for hydrogen production has emerged as a research hotspot because it enables the use of non-noble metal catalysts. However, the anodic four-electron proton-coupled reaction exhibits sluggish kinetics, which seriously hinders its industrialization. Here, a strontium-doped nickel-iron selenide precatalyst was prepared via a hydrothermal method, and it was in-situ reconstructed into Sr-NiFeOOH ultrathin nanosheets under alkaline oxygen evolution reaction （OER） conditions. Transmission electron microscopy （TEM） was used to characterize the morphology. X-ray absorption spectroscopy （XAS） was employed to explore the valence states and coordination environments of the bimetallic sites. Linear sweep voltammetry, Tafel slope, and electrochemical active surface area were utilized to evaluate the OER catalytic performance. The Sr-NiFeOOH ultrathin nanosheets are rich in bimetallic vacancies. Extended X-ray absorption fine structure （EXAFS） results confirm the enhanced covalency of metal-oxygen bonds to activate lattice oxygen. Meanwhile, the bimetallic vacancies strengthen the valence electron coupling between metal sites and interfacial hydroxyl groups, facilitating the replenishment of lattice oxygen. These effects synergistically improve the catalytic activity and structural stability. In the AEMWE system, the catalyst delivers a large current density of 2.75 A·cm⁻² at a cell voltage of 2 V, and maintains stable operation for 123 h at industrial current densities without obvious degradation. Therefore, the low-cost and high-efficiency catalyst exhibits promising practical industrial prospects and provides a rational design strategy for low-carbon industrial transformation.