The invention discloses a method for producing a high-purity titanium sponge by an inverted U-shaped combined furnace. According to the method, titanium tetrachloride with the purity higher than 99.99% and magnesium metal are subjected to reduction distillation to obtain high-purity titanium sponge lumps; the high-purity titanium sponge lumps subjected to cutting on bottom cap edge, and crushed and packaged to obtain the high-purity titanium sponge; the impurity content of the raw material in the production process is controlled; the impurity content (wt%) is reduced to 1*10 <-4> in the TiCl4purification process; molten high-purity magnesium is used as a reducing agent; a pure titanium cylinder body is arranged in a reactor in the reduction-distillation process; the contact area of the titanium lumps and the steel reactor is reduced; the phenomenon that products are polluted by Fe, Ni, Cr, Al and Si elements in the reactor is greatly reduced; and the purity of the finally obtained sponge titanium is 99.95% or above.