The invention belongs to the technical field of sponge titanium and particularly relates to a vacuum distillation method of sponge titanium. In order to solve the technical problems that the sponge titanium contains a plurality of impurities and is unstable in quality which are easily caused by the existing vacuum distillation method, the invention provides a vacuum distillation method of sponge titanium. The vacuum distillation method of sponge titanium comprises the following steps: a, putting the sponge titanium in a distillation electric furnace, vacuumizing and distilling, reducing the pressure in the electric furnace to 100Pa in 20-30 hours, then reducing the pressure in the furnace to 8-10Pa in 30-50 hours; b, continuously vacuumizing, reducing the pressure in the furnace from 8-10Pa to be less than 4Pa in 30-50 hours, keeping the pressure for 40-60 hours, and keeping the vacuum degree of the furnace at 8-10Pa for more than or equal to 90 hours. The method is capable of reducingthe content of the impurities in the sponge titanium, improving the quality of the sponge titanium, reducing the distillation time, reducing the energy consumption and reducing the production cost, and has important practical significance.