Preparation of Mg-Li alloys by vacuum silicothermic reduction process was investigated. XRD was employed to analyze the phase composition of the product and slag. SEM was used to characterize the condensation morphology of the product. The results show that the main phase of the product is Mg and that of slag is Ca2SiO4. The product successively presents lamellar, short rod-like and flocculent shape along with the condensation. When adding no fluorite, the impacts of extraction conditions, including ferrosilicon addition, temperature, compacting pressure and holding time, on Mg and Li recoveries were evaluated. Under the conditions of temperature of 1250 °C, ferrosilicon addition of 110%, compacting pressure of 15 MPa and holding time of 150 min, Mg and Li recoveries are 81.38% and 99.58%, respectively