The present invention discloses a low valence state titanium chloride-containing electrolyte preparation method, wherein the low valence state titanium chloride is titanium trichloride and/or titanium dichloride, and the preparation method is characterized by comprising: under a non-oxidizing gas atmosphere, adding a mixture of metal magnesium powder and liquid state titanium tetrachloride to a molten salt to make the metal magnesium powder and the titanium tetrachloride be subjected to a contact reaction, wherein a molar ratio of the metal magnesium powder to the titanium tetrachloride is 1:1-2. The present invention further provides a metal titanium preparation method, which comprise carrying out electrolysis on an electrolyte, wherein the electrolyte is the electrolyte prepared by using the preparation method of the present invention. The low valence state titanium chloride-containing electrolyte preparation method has the following advantages that: the low valence state titanium chloride yield is high, the reaction efficiency is high, and the valence state of the titanium in the prepared low valence state titanium chloride can be adjusted by controlling the molar ratio of the metal magnesium powder to the liquid state titanium tetrachloride.