A 3D electrode system（3D-Ti/Pt-SS-AC）was constructed using modified activated carbon as particleelectrodes to treat cyanide⁃containing wastewater generated by a gold smelting plant. The experimental results showedthat after 150 min of reaction, the removal rates of free cyanide and total cyanide compounds reached 99.9 % and96.04 %, 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. XRDcharacterization detected characteristic diffraction peaks of Cu oxides and Fe, while XPS analysis observed characteristicpeaks of Zn 2p3/2 and Zn 2p1/2 orbitals, confirming effective metal deposition. FTIR analysis showed a decrease inoxygen⁃containing functional groups on the particle electrode surface after the reaction compared with before, indicatingthat these functional groups participated in the reaction process by providing active sites and enhancing catalyticperformance. This study confirms the feasibility of the 3D 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.