Helianthus tuberosus L.was used as the raw material for extracting inulin with extraction of hot water.On the base of single factor screening,such as temperature,time,volume of adding water,pH and times of extraction,the uniform design was adopted for getting the optimal mixed technique parameters,and was verified by experiment.The result indicated that extraction rate of inulin reached 16.04 % with temperature at 68 ℃,for 70 minutes,1∶21 of ratio of liquid to material and 2 times of extraction.