Severe acute pancreatitis is a very serious and dangerous disease, the patient’s risk period is as follows: 1, within 72 hours of the onset of the patient, this is the period of inflammatory response is obviously expanded, called the acute inflammatory response period; 2, the second risk period is the course of the disease 10-14 days, the patient will find abdominal pain relief, can drink and eat, at this time the patient can suddenly develop a high fever, body temperature of 38 ℃ – 39 ℃, abdominal pain increased, sudden onset of abdominal distension, called the infection period. At this time, the patient may have a sudden onset of high fever with temperature of 38℃-39℃, increased abdominal pain and sudden abdominal distension, which is called the infection phase. During the early treatment, some bacteria in the intestinal tract can be displaced to the abdominal cavity, and due to the necrotic material and exudation of the pancreas, bacteria can grow in large quantities in this environment, and in about 10 days, bacteria will grow to a certain extent, causing systemic infection, such as sepsis and septicemia may occur. This is the most likely peak of death during the patient’s hospitalization, within 3 days and about 10-14 days; 3. The third dangerous period, called the complication period, has some serious pancreatitis, the pancreatic necrosis will be wrapped in the patient’s abdominal cavity, the outside is a relatively hard shell, there may be secondary infection. In some patients, the necrotic part of the pancreas will form an encasement of some important blood vessels and erosion of the gastrointestinal tract. 4-8 weeks after the patient is discharged from the hospital, hemorrhage of the gastrointestinal tract will occur secondary to the erosion of the large blood vessels in the abdominal cavity by the necrotic material of the pancreas. Some patients will have secondary perforation of the gastrointestinal tract, which is also caused by the erosion of necrotic material into the stomach and intestinal walls. The third peak of death is relatively rare and is seen in patients with very severe disease, and more patients admitted to the ICU do not experience this condition. After discharge, patients with acute pancreatitis must follow medical advice and return to the hospital for review, sometimes by ultrasound, ultrasound endoscopy, CT, to see if the patient has late complications.