Anal fistula is the abbreviation of anorectal fistula, known as hemorrhoids in Chinese medicine, which is an infected granulomatous canal formed by the rectum, anal canal and perianal skin communicating. The incidence of anal fistula is second only to that of hemorrhoids, accounting for about 10% of anal morbidity, mostly in young and middle-aged men. Anal fistulas are often accompanied by a history of varying degrees of perianal swelling and pain and ulceration. The patient will have recurring painful perianal swelling, ulceration, pus, blood and other manifestations from time to time after the formation of anal fistula. It is advisable to treat anal fistula patients as early as possible once they are diagnosed to avoid repeated septicemia and the formation of multiple fistulas, making it more difficult for later surgery, as well as to reduce the patient’s pain earlier, protect the anal function from being affected and prevent the possibility of anal fistula cancer.