Abstract: Objective　To observe the clinical efficacy of two kinds of intersphincter approach in the treatment of high simple anal fistula. Methods　Seventy-two patients with high simple anal fistula were randomly divided into experimental group (n=36) and control group (n=36). The experimental group was treated with TROPIS (modified transanal opening of intersphincteric space), and the control group was treated with LIFT (ligation of the intersphincteric fistula tract). The hospitalization time, operation time, cure rate, anal function, pain index, wound area, postoperative complications and clinical effect were compared between the two groups. Results　The operation time was shorter in the experimental group than that of control group, and the cure rate was higher than that of control group (P＜0.05). There were no significant differences in length of hospital stay, anal function and wound area before and after operation between the two groups. The pain index values were lower at the first, third and seventh day after surgery in the experimental group than those of the control group (P＜0.05). The total incidence of complications was higher in the control group than that in the experimental group, and the operative efficiency was lower than that in the experimental group (P＜0.05). Conclusion　The modified TROPIS operation can increase cure rate, shorten the operation time, reduce postoperative pain and reduce postoperative complications, which is worthy of being popularized in clinical application.