Objective To explore the efficacy of tunnel thread dragging and internal opening incision in the treatment of horseshoe anal fistula,and to summarize the clinical experience and application value.Methods Based on digital table extraction method,104 patients with horseshoe anal fistula who had been hospitalized during the period of September 2009 to September 2011 were randomly divided into study group and control group,52 for each group.The study group received tunnel thread dragging and internal opening incision,while the control group received conventional fistulectomy therapy.The efficacy,average healing time,and healing time of branch fistula were compared between the two groups.Results In the study group,52 patients were cured after the prirnary procedure,with a cure rate of 100％;no complications occurred;and no recurrence developed in a 6-month follow-up.While in the control group,42 patients were cured,with a cure rate of 80.8％;10 patients developed false healing due to improper dressing changes and were cured after receiving secondary procedure,with a repeat procedure rate of 19.2％;18 patients developed postoperative complications,with a rate of 34.6％;and 2 patients developed recurrence in a 6-month,with a rate of 3.8％.The cure rate for primary procedure,rate of secondary procedure,and rate of postoperative complications differed significantly between the two groups(P＜0.05).Average healing time and healing time of branch fistula also differed significantly(P＜0.05).Conclusions Tunnel thread dragging and internal opening incision for horseshoe anal fistula is efficacious and is obviously superior to traditional fistulectomy.It can significantly shorten the course of treatment,accelerate healing of branch fistula,reduce complications,lower the rate of secondary procedure,and improve clinical efficacy and safety and thus has important value in clinical application.