Purification salt conversion method of micafungin

The present invention relates to a purification salt conversion method of micafungin. According to the present invention, the method is mainly characterized in that a buffer solution of a corresponding salt and a micafungin N, N-diisopropylethylamine salt are subjected to ion exchange on a reverse phase preparative chromatographic column so as to complete salt conversion, remove the related impurities, and achieve the purification effect; and the process has characteristics of stable and controllable process, easy and convenient operation, easy industrial production achieving, and easy product quality control.