Method for extracting acetylisovaleryl tylosin

The invention provides a method for extracting acetylisovaleryl tylosin by a salting-out method. The key point of the method is that adequate sodium chloride or potassium chloride or sodium sulfate or potassium sulfate or ammonium sulfate is added in acetylisovaleryl tylosin-contained biotransformation percolate or acetylisovaleryl tylosin-contained water solution; under a condition that the pH value of the percolate is more than six, the acetylisovaleryl tylosin is separated out of the percolate; subsequently, the acetylisovaleryl tylosin is obtained by solid-liquid separation; wherein the yield of the crude extract is more than 98%; subsequently, the crude extract is purified further; furthermore, the crude extract and the tartaric acid generate the salt in carbinol; finally, the acetylisovaleryltylosin tartrate is obtained by de-menstruum, with the yield of more than 91%.