This study introduces an ultrathin, zincophilic ZnS solid electrolyte interphase (SEI) layer to regulate the electric double layer (EDL) in aqueous zinc-ion batteries (AZIBs). The ZnS layer, deposited on the zinc anode, reduces the potential drop over the Helmholtz layer and suppresses the diffuse layer, leading to decreased EDL repulsion and uniform zinc deposition. This results in enhanced charge distribution, reduced side reactions, and inhibited zinc dendrite formation. The Zn@ZnS electrode demonstrates superior electrochemical performance, including a symmetric cell with a stable cycling life of 3,000 hours at 1 mA cm⁻² and a high rate performance of 160 mA g⁻¹ at 0.1 A g⁻¹. When used in full cells with I₂/AC and MnO₂ cathodes, the Zn@ZnS anode shows high specific capacities, long cycling stability, and suppressed "shuttle effects." The work highlights the importance of EDL regulation for achieving stable and efficient AZIBs.This study introduces an ultrathin, zincophilic ZnS solid electrolyte interphase (SEI) layer to regulate the electric double layer (EDL) in aqueous zinc-ion batteries (AZIBs). The ZnS layer, deposited on the zinc anode, reduces the potential drop over the Helmholtz layer and suppresses the diffuse layer, leading to decreased EDL repulsion and uniform zinc deposition. This results in enhanced charge distribution, reduced side reactions, and inhibited zinc dendrite formation. The Zn@ZnS electrode demonstrates superior electrochemical performance, including a symmetric cell with a stable cycling life of 3,000 hours at 1 mA cm⁻² and a high rate performance of 160 mA g⁻¹ at 0.1 A g⁻¹. When used in full cells with I₂/AC and MnO₂ cathodes, the Zn@ZnS anode shows high specific capacities, long cycling stability, and suppressed "shuttle effects." The work highlights the importance of EDL regulation for achieving stable and efficient AZIBs.