Abstract: The titanium-containing oxide slag, low-purity silicon and slagging fluxes are subject to reduction smelting together, and a bulk Si—Ti intermediate alloy is obtained by slag-metal separation; the obtained bulk Si—Ti intermediate alloy is crushed into Si—Ti intermediate alloy particles; and the obtained Si—Ti intermediate alloy particles are used as an anode, metallic molybdenum or metallic nickel as a cathode, metallic titanium as a reference electrode, and NaCl—KCl—NaF together with small amounts of Na3TiF6 or K3TiF6 as a molten salt, to carry out the electrolysis under a high-purity argon atmosphere at a temperature of 973 K. Ti in the Si—Ti intermediate alloy particles dissolved at the anode and deposited at the cathode, while Si in the Si—Ti intermediate alloy particles fell off from the anode as metallic silicon powder.