A reuse apparatus of eutectic salt waste produced in an electro refining process and a method thereof is a technology that in order to collect the eutectic salt of the eutectic salt waste, oxidizes/precipitates nuclides (rare earth and TRU) within the eutectic salt waste, an oxygen dispersing method is used to perform a layer separation into the eutectic salt layer and the precipitate layer. Then, the precipitate layer and eutectic salt layer are separated and collected, so that the eutectic salt layer is directly reused and the eutectic salt within the precipitates is reused by separating and collecting it using distillation/condensation processes. The reuse apparatus of the eutectic salt waste and a method thereof thereby increases the collecting efficiency of the eutectic salt and allows the compositions of the collected eutectic salt to have the same compositions as the eutectic salt used in the electro refining process.