Abstract: Thermodynamic simulation of lead side-blowing oxidation smelting process was carried out by FactSage software. The calculated equilibrium phase composition was consistent with the actual output, which verified the feasibility of thermodynamic analysis. The effects of oxygen-to-feed ratio and melting temperature on the distribution ratio of elements among each equilibrium phase were studied. The results showed that with the increase of oxygen-to-feed ratio, the proportion of valuable elements such as lead and copper into high lead slag will raise, and the desulfurization effect of furnace charge will be better, but at the same time, the impurity content in lead liquid will rise correspondingly; Increasing the smelting temperature is beneficial to reduce the sulfur content of slag and improve the grade of crude lead. But higher temperature will aggravate the volatilization of valuable metal elements such as lead and zinc. The lead side-blowing oxidation smelting could be controlled, by using the macro process to calculate batch balance. Under the condition that the quality of crude lead and high-lead slag reaches the desired value, the process is optimized via comprehensively considering the direct yield of valuable elements and the soot rate. It is suggested that the oxygen-to-feed ratio should be controlled at about 124 m³/t and the smelting temperature at about 1 067 ℃.