The invention provides a method for preparing sponge titanium from sodium fluotitanate by aluminothermic reduction, comprising the following steps: a reaction step: aluminum and zinc are mixed under a vacuum state, and sodium fluotitanate is then added into the mixture for reaction; a separation step: the product resulting from the complete reaction stands still and is then introduced with inert gas, and NaF and AlF3 in upper-layer liquid phase are extracted; and a distillation step: Zn in the remaining product Zn—Ti is distilled out under a vacuum state, wherein the mass ratio of the aluminum to the zinc is 1:2 to 1:10.