Ultrasonication was used to prepare silk fibroin nanofibers directly from dumming silk fiber in aquous solution.The existing problems,the key influencing factors and different pretreated methods in ultrasonic preparation of SFN were analyzed detailly.The SFF pretreated with mixed solutions of sodium carbonate and sodium phosphate could fully Ultrasonication was used to prepare silk fibroin nanofibers directly from dumming silk fiber in aquous solution. The existing problems, the key influencing factors and different pretreated methods in ultrasonic preparation of SFN were analyzed specifically. The SFF pretreated with mixed solutions of sodium carbonate and sodium phosphate could fully