The full name of anal fistula should be anorectal fistula, also known as anal leakage in Chinese medicine, is a tube formed when the soft tissue around the anus and rectum is infected with pus and then ulcerated or artificially cut open, this tube starts as one and can have more than one as the disease develops. The inner mouth of the canal is the entrance to the infection, and more than 90% of them are located in the anal sinus about 4 cm from the anal opening at the dentate line. The outer mouth of the canal is the ulcerated or surgical incision, mostly outside the anus, but also inside the anus or in the rectal wall. Anal fistula is a common anorectal disease, accounting for about 10% of anorectal morbidity in China, with young adults aged 20-40 years old, and infants and children are not uncommon. The effects are recurrent perianal infections, swelling and pain, scarring of the perianal tissue, and a few fistulas of long duration, more than 10 years, with a certain tendency of malignant transformation. Like paranal abscesses, anal fistulas differ from infections in other parts of the body in that they occur near the anorectum and have a fixed source of infection in the anal or rectal cavity, the internal orifice, and the lesion is located in the anal sphincter, whose diastole and contraction affects the drainage of pus. Therefore, there is no possibility of self-healing of anal fistula and paranal abscess once they occur, regardless of their severity, and medication will only alleviate the symptoms, and the only way to achieve clinical cure is through surgical treatment. There have been many attempts to treat fistulas and perianal abscesses with methods other than surgery, but they have all ended in failure, to say the least, and so far no non-surgical methods have been found to cure them. The purpose of anal fistula surgery is to cut open the fistula, remove the internal opening, completely eliminate the source of infection, allow the fistula to drain freely, and allow new granulation tissue to grow upward from the bottom of the wound and gradually fill in the wound.