<p>This study systematically investigated the process differences between aluminum and silicon as reductants in the vacuum reduction of magnesite. The objective is to optimize the reduction process by minimizing both the temperature and time, while ensuring a reduction degree that meets or exceeds that of the Pidgeon process. The results indicated that elevating the reduction temperature significantly enhanced magnesium reduction efficiency, whereas prolonging the reaction time showed limited effectiveness. Under identical reaction parameters, aluminothermic reduction achieved a higher reduction degree compared to silicothermic reduction. Adding CaO promoted the reaction by binding with SiO₂ or Al₂O₃ in the products. For silicothermic reduction conducted at 1200 °C for 2 hours, a reduction degree of 83.7 pct was attained with a CaO/MgO molar ratio of 0.8. However, for aluminothermic reduction at 1100 °C for 2 h, a comparable reduction degree of 83.08 pct was achieved with a lower CaO/MgO molar ratio of 0.5. These findings indicated that aluminothermic reduction required lower reaction temperatures and less CaO addition to achieve a similar reduction degree compared to silicothermic reduction. Phase composition analysis <i>via</i> XRD and SEM–EDS revealed that Ca₂SiO₄ was the dominant phase in the silicothermic reduction slag, whereas Ca₁₂Al₁₄O₃₃ emerged as the primary phase in the aluminothermic reduction slag.</p>