The study presents a novel seawater electrocatalyst, Pt-Ni₃N@V₂O₃/NF, designed for efficient and durable hydrogen production. The catalyst incorporates a protective V₂O₃ layer to modulate the microcatalytic environment and create dual-active sites consisting of low-loaded Pt and Ni₃N. This design results in an ultralow overpotential of 80 mV at 500 mA cm⁻², a mass activity 30.86 times higher than Pt-C, and maintains performance for at least 500 hours in seawater. The anion exchange membrane water electrolyzers (AEMWE) assembled with this catalyst demonstrate superior activity and durability under industrial conditions. In situ localized pH analysis reveals that the V₂O₃ layer acts as a Lewis acid, sequestering excess OH⁻ ions, mitigating Cl⁻ corrosion, and preventing alkaline earth salt precipitation. This catalyst provides a promising and cost-effective approach for large-scale sustainable green hydrogen production from seawater.The study presents a novel seawater electrocatalyst, Pt-Ni₃N@V₂O₃/NF, designed for efficient and durable hydrogen production. The catalyst incorporates a protective V₂O₃ layer to modulate the microcatalytic environment and create dual-active sites consisting of low-loaded Pt and Ni₃N. This design results in an ultralow overpotential of 80 mV at 500 mA cm⁻², a mass activity 30.86 times higher than Pt-C, and maintains performance for at least 500 hours in seawater. The anion exchange membrane water electrolyzers (AEMWE) assembled with this catalyst demonstrate superior activity and durability under industrial conditions. In situ localized pH analysis reveals that the V₂O₃ layer acts as a Lewis acid, sequestering excess OH⁻ ions, mitigating Cl⁻ corrosion, and preventing alkaline earth salt precipitation. This catalyst provides a promising and cost-effective approach for large-scale sustainable green hydrogen production from seawater.