Method for preparing enramycin crude product

The invention discloses a method for preparing an enramycin crude product. The method comprises the following steps of: 1, taking streptomycete fermentation liquor for generating enramycin; 2, adding a polar organic solvent of which the volume is the same as that of the fermentation liquor into the fermentation liquor to obtain a leaching solution; 3, performing solid-liquid separation to obtain filtrate and filter residues, and collecting the filtrate; 4, passing through a polyether sulfone ultrafiltration membrane with the molecular weight cutoff of 30KD, and collecting filtrate from the ultrafiltration membrane; 5, passing through a polyether sulfone nanofiltration membrane with the molecular weight cutoff of 5KD; 6, passing a disposable nanofiltration membrane filtrate through a polyether sulfone nanofiltration membrane with the molecular weight cutoff of 1KD, and collecting the cutoff solution; 7, adding absolute methanol or absolute ethyl alcohol into the cutoff solution, adding methyl tertiary butyl ether or ethyl ether into the cutoff solution, stirring and standing; and 8, separating and drying the precipitate in the step 7. According to the method, the enramycin crude product can be obtained.