Pre-sacral cysts are less common in clinical practice, and their misdiagnosis and treatment rates are high because of their low incidence, deep location, and susceptibility to secondary infection. Most patients are misdiagnosed as perianal abscess and repeatedly operated without postoperative wound healing, which is extremely painful for patients and affects their work and study. Since 2009, our department has treated five patients with presacral cysts, all of whom were misdiagnosed by outside hospitals after surgery and were cured after treatment. The diagnosis method, clinical characteristics and cure experience are reported as follows. 1.Clinical data The patients in this group were 2 males and 3 females, aged 24-44 years old, with an average of 34.41 years. 5 patients, 3 cases with a disease duration of 1 to 2 years, and the remaining 2 cases were 10 years and 15 years respectively. All of them were misdiagnosed in local hospitals and underwent radical surgery for anal fistula or abscess, with the number of operations ranging from 2 to 4. Three cases came to the hospital with symptoms of recurrent pus flow from the paranal and ulcerated mouth, and two cases came to the hospital with symptoms of swelling and pain in the paranal and sacrococcygeal areas. There were 2 cases of incomplete anal incontinence, 1 case of anal overflow, and 2 cases of normal anal function. 2. Special examinations: X-ray fistulography and endorectal ultrasound were performed after the patients came to the hospital, and anorectal MRI could be done if necessary. ① X-ray fistulography showed the fistulas of the anal canal and the location of the pus cavity on the pubic-caudal line; high-density shadowing was seen in the presacral area, the depth of the internal opening from the anus and the flow of contrast into the rectum. ② Ultrasound in the rectal cavity often detects hypoechoic dark areas or strong echogenic clusters in the rectal cavity and perianal area up to 12-15 cm deep from the anal margin, mostly located in the presacral area, with generally regular borders, clear boundaries with surrounding tissues and regular morphology. 3.Surgical treatment under anesthesia in the saddle area. The perianal skin and subcutaneous skin are incised radially from the ulcer, and the cystic cavity under the rectal wall is found, which is usually located above the anal raphe, and white clear pus is usually seen flowing from the incision. In case of bleeding, electrocoagulation with an electric knife is used to stop the bleeding. After the operation, the medicine was changed routinely and attention was paid to keep the drainage unobstructed to prevent pseudo-healing. 4. The results of 5 patients in this group were returned 3-6 months after surgery, and 5 cases were cured, all of which had complete wound healing and normal anal function in 3-5 months. There were no recurrence cases. There were no complications such as anal stricture or anal overflow. One case with a slight sensation of anal downward movement had a history of anorectal inflammation before surgery, and the symptoms disappeared after discharge from the hospital with outpatient medication. Pre-sacral cyst is an infectious disease with epithelial cells growing in the lesion, which is highly prone to recurrence. There is no way to cure it completely, and surgery can only serve to temporarily eliminate the symptoms and cannot cure it. However, as anorectal clinicians should not ignore it, they should understand the occurrence, development and clinical characteristics of this disease, and they should consider many aspects and identify it in time to relieve the patients’ pain when they meet the suspected patients concerned.