Patients with anal fistula have their own personal experience and pain. Once a fistula is formed, there is very little chance of self-healing, and the complication of the fistula brings a lot of trouble and certain harm. The first is that the pus contaminates the underwear, and after strenuous activity can cause the pus to overflow, local irritation, skin friction, itching, very painful, affecting work and study, and over time can make the body weak and thin, mental discomfort, resistance to disease, anemia, and more frequent attacks, forming a mutual cause and effect. As a result of repeated episodes, the pus can penetrate the wall and spread along the sphincter gap to form multiple, complex anal fistulas, which not only makes treatment difficult, but also affects the normal physiological function of the anus. The multiplicity of anal fistulas can form rectovaginal fistulas, rectourethral fistulas and rectal bladder fistulas, which endanger the surrounding organs, and they have a tendency to become malignant. The number of cases of anal fistula combined with anorectal cancer has been increasing in recent years. As early as 1936-1955, Mark Hospital found 8 cases of anal fistula with rectal colloid carcinoma; in 1966, Heidenreich synthesized European and American literature, there were 131 cases of anal fistula with anorectal cancer, mostly mucinous adenocarcinoma; in 1981, the Japanese Society for Colorectal Cancer Research counted the number of anal fistula carcinomas found throughout Japan. There were 95 cases of anal fistula lasting for more than 5 years and 80 cases for more than 10 years, with mucinous adenocarcinoma accounting for the majority. It is generally believed that the carcinoma is related to the stimulation of long-term chronic inflammation. The formation of hard nodes, mucus secretion and pain are often the precursors of cancer, and the cancer rate is higher in cases older than 10 years, which deserves our attention. Thus, active treatment of anal fistula can prevent the occurrence of rectal cancer.