<p>Copper slag (CS), rich in copper and iron, has significant potential for secondary utilization. Current research on the utilization of CS primarily focuses on the building materials, while metal recovery is mostly limited to the extraction of copper or iron individually, resulting in modest economic returns. In this study, copper-iron alloys were prepared from coke melt-reduced CS, and the effect of carbon content on the phase transition of the system was first thermodynamically calculated. Then effect of the investigated carbon content and system alkalinity on the recovery of Fe and Cu was investigated, and the migration patterns of Fe, Cu, Zn, Pb and S in combination with XRD, XRF and FE-SEM were summarized. Meanwhile, thermodynamic calculations combined with thermogravimetric analysis and heat treatment jointly were used to analyze the phase change behavior with increasing temperature during the reduction of CS, providing new ideas and directions for the reduction process. Under optimal conditions, the recovery of iron reached 97.6% and that of copper was 79.7%; the corresponding crude alloy contained 98.12% Fe, 0.62% Cu and 0.075% S. The CaO + Fe₂SiO₄ composite phase underwent two phase transitions near 225°C and 745°C, respectively. At 1220°C, fayalite in the CS was completely dissociated by CaO.</p>