The invention is related to the method of polymyxine B recovery from fermentation broth for the purpose of pure substance recovery. The invention mentioned above is obtained by using the method of polymyxine B recovery from fermentation broth according invention, which abstract is characterized by, that the filtrate is obtained from fermentation broth, its pH and color is adjusted and purified on non-ionogenic synthetic adsorbents of polystyrene type with specific surface 500 till 1000 m.sup.2.g.sup.-1 and fabric size 3 till 30 nm. The polymyxine B is eluated from adsorbent by aqueous solution of organic solvent. The polymyxine B base is coagulated from eluate after adjustment of pH to alcaline area. The polymyxine B base is converted by mineral acid to polymyxine B salt solution, from which is obtained crystal substance by drying.