A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash (BFA). The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using thermodynamic equilibrium calculation and the principle of minimum free energy. The results showed that the main reaction in the system is the reduction of ZnFe₂O₄ and iron oxides. Over the full temperature range, iron oxides were more easily reduced than zinc oxides. Regardless of the amount of CO contained in the system, the reduction of ZnO to Zn was difficult to proceed below the boiling point (906 °C) of Zn. When the reduction temperature is below 906 °C, the reduction process of zinc ferrate was ZnFe₂O₄ → ZnO; when the reduction temperature is above 906 °C, its reduction process becomed ZnFe₂O₄ → ZnO → Zn(g). The metallization and dezincification rates of the BFA gradually increased with increasing reaction temperature. As the C/O ratio increased, the metallization and dezincification rates first increased and then decreased. The effect of reduction time on BFA reduction was similar to that of reaction temperature.