<p>Photocorrosion triggered by the unconsumed photogenerated holes severely deteriorates the photocatalytic efficiency and stability of semiconductor photocatalysts, especially in seawater with complex ions. Here, we report a hierarchical hollow ZnIn₂S₄ heterostructure integrating an inner CoO_x nanocage and atomically dispersed Pt anchoring at surface S vacancies for hydrogen evolution from natural seawater (23.88 mmol g⁻¹ h⁻¹) and pure water (48.99 mmol g⁻¹ h⁻¹) under visible light. The dynamic Co²⁺/Co³⁺ self-reconstruction of the inner CoOx cage effectively consumes photogenerated holes, while the outer Pt₁ single atoms localized at S vacancies serve as electron sinks to facilitate electron extraction and proton reduction. Benefiting from the dynamic hole-scavenging mechanism via oxidation self-reconstruction, the Pt₁-ZnIn₂S₄@CoO_X photocatalyst exhibits enhanced durability against alkali metal ions in seawater and maintains high reactivity for long-term hydrogen evolution. This work underscores the importance of light-induced transition metal dynamic self-reconstruction within hierarchical hollow heterostructure photocatalysts for sustainable hydrogen evolution.</p>