<p>The removal of cadmium in zinc sulfate solution using zinc has the problem of cadmium re-dissolution, especially with high copper-cadmium, which leads to an increase in the zinc consumption and a poor cadmium removal effect. To address this challenge, a method to efficiently remove cadmium by copper ion regulation was proposed. The experimental results indicated that the cadmium removal rate was increased from 64.23% to 95.56% by copper ion gradient adjustment under the same process conditions. Additionally, Copper ion gradient regulation resulted in high-quality copper slag and improved the grade of the purification slag, enabling efficient copper resource recovery and reducing the difficulty of cadmium resource recovery. The behavior of zinc-substituted cadmium at varying Cu/Cd molar ratios was analyzed by characterization methods such as XRD, SEM-EDS, and XPS, and the reaction mechanism of cadmium cementation was revealed in combination with thermodynamic analysis. Cadmium deposits on a copper substrate, forming CuCd intermetallic compounds. These compounds have higher potentials than metallic cadmium, which increases the driving force for the cementation reaction and accelerates the overall process. This method improves the utilization rate of zinc and is an efficient and environmentally friendly method of cadmium removal for high copper-cadmium zinc sulfate solution.</p>