Background: High anal fistula (HAF) is a refractory infectious disease. Surgery is the most effective way to treat HAF. Dressing change is an indispensable part of the rehabilitation process after surgery. The purpose of this study is to provide feasibility and evidence of safety for the implementation of a simplified dressing change after loose combined cutting seton (LCCS) surgery and to offer a better method for clinical treatment and postoperative rehabilitation of HAF. Methods: In this single-blind randomized controlled trial, 76 patients diagnosed with HAF will be randomly divided into two groups: the simplified dressing change group (n=38) or the traditional debridement and dressing change group (n= 38). Compared with traditional debridement and dressing change, simplified dressing change was conducted without mechanical debridement and disinfection. All patients were treated surgically with the LCCS and dressing change. Postoperative follow-up will be carried out on the 3rd, 7th, 14th, 21st, and 180th day after the operation. The primary outcomes will be: complete healing rate of wound and fistula, long-term recurrence rate, poor wound healing rate, and complete wound healing time. The following secondary outcomes will be evaluated: postoperative pain using a visual analogue scale (VAS) score, wound secretions, edema, granulation shape, depth of wound, duration of each dressing change, and incidence of adverse events. Discussion: Dressing change after HAF surgery is a necessary stage of recovery after anorectal surgery. Effective dressing change can reduce false healing and increase the cure rate. However, traditional dressing change takes a long time, and the patient endures severe pain. We have found that the dressing change process can be simplified in the clinic for patients treated with LCCS. In particular, simplification of the dressing change process may be related to the unobstructed drainage provided by the combination of LCCS and the separation of the dotted line. We will treat HAF using LCCS and compare the simplified dressing change method after the operation with traditional routine debridement and dressing change to demonstrate whether the simplified dressing change can be used in patients with HAF treated with LCCS.