Anal fistulas primarily arise from local perianal abscesses that are not actively treated, repeatedly occur, or from severe pus cavity inflammation that causes the abscess to rupture locally, resulting in the formation of an anal fistula. An anal fistula typically has a characteristic internal opening and external opening, as well as a fistula tract connecting them. After the occurrence of an anal fistula, it is recommended that the patient undergo surgery as soon as possible. The surgical method mainly used for anal fistulas is the cutting and threading surgery. If it is a high-position complex anal fistula or there are multiple external openings and branches, the patient needs to complete related examinations, mainly focusing on local perianal color ultrasound or pelvic MRI, which are most important. After clarifying the direction of the fistula branches, a thorough and definitive surgical treatment for the anal fistula can be carried out.