Preparation method of demethyl aureomycin hydrochloride

The invention relates to a novel technology of demethyl aureomycin hydrochloride, which solves the problems of tedious process, difficult control, reduced yield due to partial precipitation of demethyl aureomycin hydrochloride when acid water is filtered, long operation time, large energy consumption and high cost, the preparation method comprises the following steps: under the temperature less than or equal to 10 DEG C, an demethyl aureomycin extract passes through a filtering medium for filtering to remove the insoluble impurity, under the temperature of 15-20 DEG C, the pH value of the filtered extract can be regulated by hydrochloric acid to 0.2-1.0 and then crystallization is carried out, the crystallization liquid is subjected to pumping filtration, crystals can be separated, wet crystals can be washed by hydrochloric acid and an organic solvent in order for 1-4 times, and then dried, According to the invention, the overall yield is increased, the steps are simple, the operation time is short, the energy consumption is less, the cost can be reduced, the process is simplified, equipments and manpower are saved, the operation is convenient, the cost is saved, thereby the method is suitable for large scale production.