Acute pancreatitis is often accompanied by elevated blood and urine amylase, which usually begins to rise 6-8 hours after the onset of the disease, peaks in 24-48 hours, then begins to decline and disappears over a period of 2-3 days. Urinary amylase, on the other hand, appears later, usually starting at 12-24 hours, peaking at 1-2 weeks, and then gradually disappearing. In severe pancreatitis, due to severe necrosis of pancreatic cells and reduced pancreatic secretion, the patient’s blood and urine amylase may not be elevated, so the severity of pancreatitis is not based on the blood and urine amylase as a criterion, but should be combined with the blood biochemistry, abdominal CT, ultrasound of the liver, gallbladder, pancreas and spleen, as well as pancreatic MRI and other related examinations to determine the severity of the disease, and then perform targeted treatment.