Anal ultrasound is usually performed mainly for the examination of inflammatory lesions, infections or perianal abscesses around the anus. Some patients with perianal abscesses, such as the formation of obvious sinus tracts and the formation of anal fistulas, can also be examined by anal ultrasound to specifically discern the location, or to view the depth of the sinus tracts and the main relationship with the external skin opening. In conclusion, anal ultrasound provides an effective imaging basis for the clinical diagnosis of various anorectal diseases, so anal ultrasound examiners should go to the hospital regularly for routine examinations. In addition, when some perianal abscesses are punctured for pathology or drainage, they can also be localized by anal ultrasound examination.