In order to recycle the ultrafine high titanium slag produced in TiCl₄ production process, the titanium slag was sintered and employed as the cathode in a Solid Oxide Membrane (SOM) electrolytic process in molten CaCl2 to prepare metal Ti. The deoxidization process of the cathode and the behavior of impurities removing were studied at an electrolytic temperature of 1150 ℃with an electrolytic voltage of 3.5 V. Results showed with the increasing of electrolytic time, the size and porosity of cathode was decreased while the particle size in cathode was increased, and after 6 hours electrolyzing metal titanium was obtained which indicated the SOM process offered a high current efficiency. The deoxidization process of this electrolysis process was carried out as: TiO₂→CaTiO₃ →Ca(Ti₂O₄) → TiO→ Ti. Results also indicated the impurities which included Al, Mn, Fe, and Si were mostly reduced to corresponding elementary substance, which were moved into melting CaCl₂. A small amount of residual impurities in cathode can be removed by washing with dilute hydrochloric acid.