This paper analyzes the sugar components of different Jerusalem artichoke (Helianthus tuberosus L.) tubers and their leaves. The results showed that the total sugar content of Jerusalem artichoke tuber accounted for more than 70% of dry weight. The content of inulin reached 77.5% on average, and the highest is "Binyu no.1" tuber. The content of inulin in the stem leaf was more than 11.73%, reaching an average of 12.93%. And the effect of inulin was then tested by functional test on constipation model mice. ICR male mice were randomly divided into blank control group, model control group, positive control group, low dose inulin group, medium dose inulin group and high dose inulin group. After 7 or 15 days of continuous inulin infusion, we observe the small intestine movement, initial stool time and amount of black stool. The results showed that inulin had a significant effect on constipation in mice. Finally, we analyse 27 varieties of Jerusalem artichoke by experiments, and select 6 varieties with high efficacy.