Abstract: The inulin is very rich in Jerusalem artichoke tuber.Fructan can be produced from the inulin.Low fructosan has a positive role in improving the intestinal function, and high fructosan can produce ultra high fructose syrup.According to research reports at home and abroad in recent years, the author reviewed theory, process flow and its latest progress of inulin extraction methods which contained hot water extraction method, ultrasonic assisted method, microwave assisted method and enzyme method, as well as acid process and enzymolysis method preparation of fructose and its physiological function.Existing problems were put forward and the future development was prospected as well.