<p>The ammonia-based zinc extraction process has gained increasing application due to the characteristics of suitable treatment of low-grade zinc oxide resources, high purification efficiency of leaching solution, and less waste discharge. However, studies on the impact of metal impurity ions during the zinc electrodeposition process in ammonia-based systems remain relatively limited. This paper systematically investigates the effects of Pb and Cd on zinc electrodeposition. The results indicate that in the zinc electrodeposition system, the impurity lead exists in forms such as Pb²⁺, PbCl⁺, Pb₂(OH)₄²⁺, and PbOH⁺, while cadmium exists as Cd²⁺, Cd(NH₃)₂²⁺, Cd(NH₃)₃²⁺, and Cd(NH₃)₄²⁺. Further electrochemical experiments reveal that with increasing concentrations of Pb and Cd in the electrolyte, the nucleation overpotential decreases, the corrosion current density increases, and the corrosion rate accelerates, which progressively hinders the deposition of cathodic zinc. Additionally, high concentrations of Pb and Cd in the electrodeposition system lead to cathodic corrosion, resulting in rough, polycrystalline dendritic cathodic zinc that is difficult to strip and inhibit zinc deposition on the electrode surface. When the Pb and Cd concentration is 0.1&#xa0;g/L, the current efficiency reaches its maximum value of 95.48 and 93.86&#xa0;pct accordingly with the power consumption of 2496.57 and 2458.69&#xa0;kWh/t. This study elucidates the impact of impurity ions on zinc electrodeposition in the ammonia-based zinc extraction process and identifies the beneficial effects of appropriate Pb and Cd concentrations on electrodeposition efficiency. This research provides a theoretical foundation and introduces an innovative method for controlling the concentration and establishing industry standards for impurity ion content in the electrolyte used in the industrial production of ammonia zinc smelting.</p> Graphical Abstract <p></p>