Perianal abscess is also a common anal disease, and delayed treatment can evolve into a complex anal fistula, bringing great inconvenience to normal life and work. 1. Lump: A small hard lump or mass appears around the anus, followed by increased pain, redness, swelling and fever, accompanied by constipation, and in heavy cases, general weakness, mental discomfort, elevated body temperature and other surface symptoms. 2. Pain: Initially, it is swelling and pain, throbbing pain when purulent, pain is aggravated when defecating, systemic poisoning symptoms are light, local swelling, redness, pressure pain, fluctuating feeling. 3. Pus flow: In the middle and late stage of getting, the pus flowing out after breaking is thin and milky, the pus mouth is depressed, the surrounding skin is blue or greenish white, and there are often multiple pus flowing out of the mouth, and it does not heal for a long time. 4. Inflammation: Severe infection and inflammation can cause high fever, chills and other symptoms of systemic toxicity. 5. Treatment: In our hospital, we treat perianal abscesses with one-time radical surgery, which avoids the pain of re-occurrence and surgery and also reduces the economic burden. Postoperative concurrent application of concentrated fumigant and topical drugs results in faster recovery and reduces hospitalization time. For complex abscesses or complicated cases where anal fistula has been formed, magnetic resonance three-dimensional imaging technology and fistula photography can be used to provide a more accurate basis for the diagnosis and treatment of some recurrent and complex anal fistulas.