Acute complications of diabetes mellitus (DKA, HHS, DLA) and acute pancreatitis (AP) are both medical emergencies, and the mechanism of their combined occurrence has not yet been determined. (2) Increased pressure in the duodenum during repeated vomiting, which causes relaxation of the hepatopancreatic sphincter and inflammation caused by the return of intestinal fluid to the pancreas; (3) Malfunction of the oxygen-carrying system of erythrocytes during diabetic acidosis and the leftward shift of the oxygen dissociation curve due to increased glycated hemoglobin, which leads to tissue hypoxia and pancreatic dysfunction; (4) Insulin deficiency. (4) Insulin deficiency. The lipolysis produces a large amount of free fatty acids to embolize capillaries and damage endothelial cells, leading to pancreatitis; ⑤ When diabetes mellitus is hyperglycemic, hyperosmolar and acidotic, the extracellular membrane is severely dehydrated and the pancreatic fluid is viscous, blocking the pancreatic duct; ⑥ Long-term dyslipidemia is prone to gallstones, and diabetes mellitus is prone to biliary tract infections and obstruction, leading to the occurrence of pancreatitis. The reasons why AP is prone to DKA, HHS and DLA: ① extensive lesions in the pancreas, damage to B cells, insufficient or lack of insulin secretion; ② stress that restricts insulin secretion, increased secretion of glucagon and glucocorticoids, causing an increase in blood glucose, serious damage to the pancreas and complications of DKA, HHS and DLA. Patients diagnosed with diabetic ketoacidosis combined with acute pancreatitis should be actively given Patients diagnosed with diabetic ketoacidosis combined with acute pancreatitis should be treated with fasting, fluid replacement, continuous small dose insulin intravenous infusion, acid suppression, reduction of pancreatic enzyme secretion, inhibition of pancreatic enzyme activity, improvement of pancreatic blood circulation, control of infection, correction of electrolyte disorders, etc. In severe cases, growth inhibitors should be given and the cause of the disease should be removed.