Anastomotic fistula is the biggest complication of esophageal cancer, and it is a fatal complication. The reasons can be summarized as follows: 1. Because most of the esophagus has to be removed, the stomach is lifted up to be sutured with the remaining esophagus, so that the digestive tract can be reconstructed completely. However, sometimes the stomach may be small in some patients, and the anastomosis will produce tension, and the anastomosis is difficult to heal under tension; 2. When the stomach is lifted, the vast majority of the supply vessels of the stomach need to be ligated, usually retaining the right artery of the gastric omentum, which is an artery supplying the entire stomach or supplying the tubular stomach, which will inevitably cause the organ blood flow is not abundant, and the anastomosis is not easy to heal in the case of ischemia and hypoxia; 3. Anastomosis technical problems, such as beginners may lead to an increased chance of anastomotic fistula; 4, instrumentation problems, a problem with a certain nail can also cause anastomotic fistula; 5, local infection, such as the possibility of contamination around the anastomosis in the anastomosis, and a limited foci of infection in the postoperative period, which are characterized by a tendency to the weak side and can sometimes penetrate through the anastomosis to the interior of the gastric cavity, which also causes postoperative anastomotic fistula ; 6, the patient’s own causes, such as older age, suffering from diabetes, preoperative malnutrition, hypoproteinemia, which are all triggers of poor healing. So some of the causes of anastomotic fistula in patients are relatively clear, while others may be a combination of factors that cause anastomotic fistula. Although every effort has been made to avoid them, it is impossible for each operator to completely avoid anastomotic fistula in clinical practice.