This study presents an ultrathin zincophilic ZnS layer as a model regulator for electric double-layer (EDL) regulation in aqueous zinc-ion batteries (AZIBs). The ZnS layer, deposited via galvanostatic electrodeposition, forms a stable and uniform interfacial layer with a thickness of 200 nm, enhancing zinc ion adsorption and suppressing side reactions. The ZnS layer reduces the potential drop over the Helmholtz layer and suppresses the diffuse layer, leading to a more uniform zinc deposition and reduced electric double-layer repulsion force. This results in a stable zinc anode with a high charge transfer rate and low overpotential. The Zn@ZnS symmetric cell exhibits excellent cycling stability, cycling for over 3,000 hours at 1 mA cm⁻² with a low overpotential of 25 mV. When coupled with an I₂/AC cathode, the cell demonstrates high rate performance of 160 mAh g⁻¹ at 0.1 A g⁻¹ and long cycling stability of over 10,000 cycles at 10 A g⁻¹. The Zn||MnO₂ battery also shows high capacity and long cycling stability of 130 mAh g⁻¹ after 1,200 cycles at 0.5 A g⁻¹. The ZnS SEI layer is effective in suppressing side reactions and zinc dendrite formation, providing a stable and efficient zinc anode for high-performance AZIBs. The study highlights the importance of EDL regulation in achieving stable and efficient zinc-ion batteries.This study presents an ultrathin zincophilic ZnS layer as a model regulator for electric double-layer (EDL) regulation in aqueous zinc-ion batteries (AZIBs). The ZnS layer, deposited via galvanostatic electrodeposition, forms a stable and uniform interfacial layer with a thickness of 200 nm, enhancing zinc ion adsorption and suppressing side reactions. The ZnS layer reduces the potential drop over the Helmholtz layer and suppresses the diffuse layer, leading to a more uniform zinc deposition and reduced electric double-layer repulsion force. This results in a stable zinc anode with a high charge transfer rate and low overpotential. The Zn@ZnS symmetric cell exhibits excellent cycling stability, cycling for over 3,000 hours at 1 mA cm⁻² with a low overpotential of 25 mV. When coupled with an I₂/AC cathode, the cell demonstrates high rate performance of 160 mAh g⁻¹ at 0.1 A g⁻¹ and long cycling stability of over 10,000 cycles at 10 A g⁻¹. The Zn||MnO₂ battery also shows high capacity and long cycling stability of 130 mAh g⁻¹ after 1,200 cycles at 0.5 A g⁻¹. The ZnS SEI layer is effective in suppressing side reactions and zinc dendrite formation, providing a stable and efficient zinc anode for high-performance AZIBs. The study highlights the importance of EDL regulation in achieving stable and efficient zinc-ion batteries.