Abstract：Objective：To observe the clinical effect of Changweining patch by ultrasonic conductance at Tianshu point(ST 25) for prevention and treatment of difficult defecation after external dissection and internal ligation for mixed hemorrhoids. Methods： A total of 90 cases of patients undergoing external dissection and internal ligation for mixed hemorrhoids were randomly divided into the control group and the treatment group，45 cases in each group. After operation，the control group was given routine nursing， and the treatment group was additionally treated with Changweining patch by ultrasonic conductance at Tianshu point(ST 25) based on the treatment of the control group. Both groups were intervened for seven days. The first defecation time as well as the pain，smooth situation and duration of defecation on the 3rd and 7th day after operation in the two groups were recorded and compared. Results：After operation，the first defecation time in the treatment group was earlier than that in the control group， the difference being significant(P＜0.05). On the 3rd and 7th day after operation，the pain and smooth situation of defecation in the treatment group were better than those in the control group， and the duration of defecation was shorter， differences being significant(P＜0.05). Conclusion： Changweining patch by ultrasonic conductance at Tianshu point(ST 25) for patients after external dissection and internal ligation for mixed hemorrhoids can improve their quality of defecation and relieve postoperative pain.