The pretreatment of the cyanide tailing by roasting and its effect on the followed comprehensive recovery of valuable metals were investigated. The results indicate that the leaching rate of gold reaches 46.14%, the magnetic susceptibility of iron is up to 86.27% when the roasting temperature is 750 °C, the roasting time is 1.25 h, and the dosage of reductant is 6%. Combined with mineral structure and principle of magnetic roasting, the promoting mechanism of gold leaching by roasting was explored. The gold exposed through the magnetic roasting is the foremost improvement for high leaching rate of gold