A sinus tract is a blind duct leading to deep tissue with a thick scar tissue wall. A postoperative abdominal wall sinus tract is an infected blind cavity that communicates with the skin after abdominal surgery, when an infected wound is caused by various reasons and does not heal for a long time. It occurs due to septic infection of the postoperative incision caused by infection of the abdominal incision, retention of foreign bodies in the incision, liquefaction of fat, etc. If poor drainage, necrotic tissue and foreign bodies are not removed in time, chronic infection of the abdominal wall is formed and unhealthy granulation tissue and scar tissue proliferate in the peri-lesion wall, gradually forming a difficult to heal infected cavity of the abdominal wall. The easy removal of foreign bodies such as unhealthy granulation tissue and threads in superficial areas and the rapid tissue repair often make the external opening of the abdominal wall sinus tract large and the internal cavity small. The vast majority of patients with postoperative abdominal wall sinus tracts clinically have a postoperative septic wound infection process, and a few patients have a stage I wound healing, but redness, pustules, and rupture appear somewhere in or near the scar after intervals of varying lengths of time. The foreign body of the thread can often be cleaned out from the wound during dressing change. In some patients, because of the superficial area and the rapid repair of epidermal tissue, the sinus opening can appear to heal transiently, so that the deep necrotic tissue cannot be discharged, and at intervals there is a local or nearby purulent inflammation. The process of “infection – healing – reinfection” is shown. The disease has the characteristics of recurrent and persistent.