Most elderly biliary patients have varying degrees of malnutrition due to the decreased functional reserve capacity of the organs and low immune function, and the recurrent course of the disease. More than 50% of such patients have varying degrees of malnutrition and weight loss, which, combined with prolonged hyperbilirubinemia, the scope of surgery and the stress caused by the often large trauma, worsen their nutritional status postoperatively, resulting in increased postoperative complications and surgical mortality. Therefore, perioperative nutritional support can help improve the nutritional status of patients and improve tolerance to surgery. The liver function damage caused by biliary obstruction, mainly hyperbilirubinemia and hypoproteinemia, is one of the important factors that delay the timing of surgery and cause surgical complications. Perioperative application of hepatoprotective drugs and nutritional support are the main measures to improve liver function and nutritional impairment. In patients with malignant biliary obstruction, preoperative albumin declined even when adequate caloric nutritional support was given, indicating that preoperative nutritional support helps to improve nutritional status but does not completely correct hepatic protein synthesis. In the case of organic disease, i.e., biliary obstruction, which has not been removed surgically, increased biliary pressure above the obstruction is the main reason for the failure to restore hepatic protein synthesis. Appropriate perioperative nutritional support can improve the nutritional status of most malnourished patients and reduce the incidence of postoperative complications. The positive effect of perioperative nutritional support on reducing the incidence of postoperative complications and operative mortality, promoting wound healing and patient recovery has been recognized in recent years. The high incidence of malnutrition in patients with malignant obstructive jaundice is mainly caused by the following factors: 1. Increased energy consumption of the body caused by the tumor itself, resulting in a large consumption of muscle and adipose tissue, while the release of proteolytic-inducing factors and fat-mobilizing factors from tumor cells further worsens the nutritional status; 2. Increased biliary pressure leads to structural and functional damage of hepatocytes, causing their metabolic 3. The body is in a stressful state after surgery, producing high catabolism, accelerated fat and muscle tissue decomposition, and in negative nitrogen balance. Due to these factors, malignant obstructive jaundice in elderly patients has a high incidence and degree of malnutrition, while the surgical trauma is relatively large, and the possibility of postoperative pancreatic, biliary or intestinal fistula is also greater. In addition, early postoperative enteral nutrition can also promote the recovery of gastrointestinal function. During the application process, the concentration, dose and drip rate of enteral nutrition solution should be adjusted according to the specific situation, and warmers and drip rate pumps should be used when available. At present, TPN still occupies an important position in nutritional support, but the application of EN has also been increasing in recent years. EN can achieve the same effect as TPN when the function of gastrointestinal tract allows, and it also has the advantages of protecting intestinal mucosal barrier, promoting intestinal function recovery, increasing blood circulation in portal system, promoting gastrointestinal hormone secretion, improving liver tolerance to nutrients and being inexpensive and physiological. In conclusion, giving certain nutritional support to elderly patients with malignant obstructive jaundice in the perioperative period and providing sufficient protein and calories can help increase protein synthesis, improve negative nitrogen balance and maintain the structural function of tissues and organs.