Surgery for anal fissure is suitable for patients with chronic anal fissure who have no obvious effect of conservative treatment, and according to the specific condition of patients, anal fissure resection, internal anal sphincter amputation and skin flap transplantation can be given. 1. Anal fissure resection: it is mainly applied to patients with chronic anal fissure who have large skin defects in the anal canal, and the operation can be carried out under local anesthesia or lumbar anesthesia, and the operation needs to take a rhombic incision to remove the wound of anal fissure, and at the same time to remove the concomitant anal papilloma and sentinel hemorrhoids, so the wound surface is mostly larger. 2. Internal sphincter amputation: mainly applicable to patients with chronic anal fissure accompanied by spasm or stenosis of anal sphincter, under local anesthesia, take an incision of about 1cm in length at the anal verge, incise the skin and separate the subcutaneous tissues, separate the internal sphincter from the sphincter groove to the dentate line, and then cut off the sphincter after picking up with hemostatic forceps, and then compress and stop bleeding and bandage at the traumatic area. 3. Skin flap transplantation: for patients with anal fissure after resection and large skin defects in the anal canal, skin flap transplantation can be given. According to the patient’s condition, professional doctors will guide the patient to choose the appropriate operation.