Abstract: A 3 D electrode system (3 D-Ti/Pt-SS-AC) was constructed using modified activated carbon as particle electrodes to treat cyanide-containing wastewater generated by a gold smelting plant. The experimental results showed that after 150 min of reaction, the removal rates of free cyanide and total cyanide compounds reached 99.9 % and 96.04 %, respectively, while the removal rates of Cu, Fe, and Zn were 98.52 %, 99.28 %, and 91.04 %, respectively. SEM and EDS analyses revealed significant deposition of Cu, Fe, and Zn on the cathode surface after the reaction. XRD characterization detected characteristic diffraction peaks of Cu oxides and Fe, while XPS analysis observed characteristic peaks of Zn 2 p₃/₂ and Zn 2 p₁/₂ orbitals, confirming effective metal deposition. FTIR analysis showed a decrease in oxygen-containing functional groups on the particle electrode surface after the reaction compared with before, indicating that these functional groups participated in the reaction process by providing active sites and enhancing catalytic performance. This study confirms the feasibility of the 3 D electrode system for the removal of cyanide and heavy metals, providing a new approach and research method for the green purification and treatment of cyanide-containing wastewater.