The present invention provides a process for producing sponge titanium, which includes the following steps: Step A: placing aluminum into a resistance furnace, vacuum pumping, introducing inert gas, heating to molten aluminum; Step B: opening a reactor cover, adding a proper amount of potassium fluotitanate to a reactor, leakage detecting after closing the reactor cover, slowly raising the temperature to 150° C., vacuum pumping, and continuously heating to 250° C.; Step C: introducing inert gas into the reactor, continuously raising the temperature to 750° C., stirring uniformly; Step D: opening a valve to adjust the stirring speed, adding molten aluminum drops, and controlling the reaction temperature to 750° C. to 850° C.; Step E: opening the reactor cover, removing a stirring device, eliminating the upper layer of KAlF4 to obtain sponge titanium. The present invention has the beneficial effects of short process flow, low cost, environmental protection and harmlessness.