A culture medium enhancer suitable for isolating culture of brucella is prepared from erythritol, glucose, animal serum, vitamins, amino acid, cell growth factors and the like. The content of ingredients in one liter of distilled water is present in the description, wherein the ingredients includes glucose, erythritol, tryptose, sodium chloride, horse serum, niacin, vitamins, vitamin B1, D-cycloserine, methylhexyl ether, polymyxin B, bacitracin, cycloheximide, nystatin, zinc sulfate, manganese sulfate, copper chloride, cobaltous sulfate, boric acid, ferric trichloride and aluminum trichloride. By using the culture medium enhancer suitable for isolating culture of brucella, growth of brucella in the culture medium can be effectively promoted while the growth of interference bacteria is suppressed. The culture medium enhancer is high in university oriented to the isolating culture of brucella, low in cost and convenient to prepare and use.