At the onset of SAP, the body undergoes ultra-high metabolic reactions characterized by protein catabolism, glycogen xenobiotic and enhanced fat mobilization, and the internal environment of the body is disturbed, resulting in rapid depletion of nutritional reserves, severe malnutrition, reduced immune defenses and increased probability of infection. The demand for nutrition in SAP patients increases. Studies have shown that the mortality rate of SAP is closely related to the inability to establish a positive nitrogen balance, and nutritional support can improve the survival rate of SAP patients. Proper nutritional support can provide substrate for protein synthesis, improve immune function and nutritional status; it can also maintain normal organ function, promote tissue repair in the late stage of injury and correct the imbalance of internal environmental homeostasis. Enteral nutrition (EN) follows the physiological route of nutrient administration, which is absorbed into the liver through the portal vein and facilitates protein synthesis, and is a safe, economical and convenient treatment method consistent with human physiological needs. Improves intestinal and systemic immune function, prevents bacterial translocation, and reduces the occurrence of enteric-derived infections and multiple organ dysfunction syndrome (MODS). Recent studies have shown that EN can stimulate the movement of intracellular lysosomes to the cell surface, reduce the release of cellular trypsin, and have a certain therapeutic effect on SAP; at the same time, EN can reduce the release of cellular inflammatory mediators, reduce the body’s systemic inflammatory response, and early EN can improve the condition of SAP patients in a timely and effective manner, shorten the course of the disease, reduce costs, and lower the incidence of complications and morbidity and mortality. Therefore, EN has received increasing attention and focus in the treatment of SAP. The timing of EN treatment at home and abroad has not yet reached a consensus, and the current status and progress of research on the timing of EN treatment at home and abroad in recent years is reviewed. In the 1990s, some scholars proposed that early implementation of EN support after partial recovery of intestinal function is important to improve the survival rate of SAP patients. The majority of Chinese scholars now advocate that EN should be started within 48-72 h after admission, if the condition is stable, the gastrointestinal function is initially restored, the inflammatory response around the pancreas subsides and the blood and urine amylase return to normal, and the patient has a certain function of the gastrointestinal tract, which is a basic prerequisite for EN. In the early stage of SAP, severe stress and inflammatory reactions lead to hemodynamic disturbances in the body, and in order to ensure the blood supply to the heart, brain and other important organs, the blood supply to the intestinal wall is reduced, and the perfusion of the intestinal mucosa is decreased, resulting in mucosal ischemia, necrosis and loss of apical cells of the villi, edema and paralysis of varying degrees, increased mucosal permeability and decreased immune barrier function. At this time, EN is not only difficult to digest and absorb, but also aggravates intestinal damage and increases the translocation of intestinal bacteria and toxins, and patients may experience severe abdominal distension that is difficult to tolerate, and also stimulates pancreatic exocrine secretion and aggravates the disease. Therefore, there is a disagreement on the best time to choose the best treatment for patients with SAP performing EN. The early onset of SAP is characterized by disruption of intestinal mucosal barrier function, intestinal bacterial translocation, absorption of intestinal-derived endotoxins, and gastrointestinal dysfunction, leading to SIRS and subsequently inducing or aggravating MODS. it is essential to actively restore and maintain intestinal mucosal barrier function, and EN can prevent intestinal mucosal atrophy, reduce intestinal flora translocation, and improve intestinal mucosal barrier function and prognosis in SAP patients. EN can prevent intestinal mucosal atrophy, reduce intestinal flora displacement, and improve intestinal mucosal barrier function and prognosis in SAP patients. The concept of “early enteral nutrition (EEN)” has been proposed, because the jejunal motility is restored earlier, so it is not necessary to wait for normal bowel sounds or anal venting to implement EN immediately. complications and reduce the rate of infection and death. In contrast to the previous concept, more and more scholars consider EEN as safe in recent years. The European Society for Parenteral Enteral Nutrition recommends starting EN within 24 h of admission for SAP patients, which is safe and feasible and results in better clinical outcomes. In the early stage of SAP, the intestinal function of some patients has not recovered, so it is difficult to correct the hypoproteinemia and negative nitrogen balance of patients by EN, and the transition of parenteral nutrition (PN) is needed, otherwise it may cause abdominal distension and increase the burden on the pancreas and the disease. Although the results of some controlled studies suggest that EN can provide sufficient energy supply, when patients have symptoms of GI intolerance such as nausea, vomiting, diarrhea and abdominal distension, the EN titration rate has to be slowed down or even suspended, and then a combination of PN is still needed to ensure sufficient energy supply. For SAP patients with combined intestinal obstruction and some critically ill patients who cannot tolerate the placement of nutrition tubes, TPN is still their nutrition route. Therefore, like EN, PN cannot be completely replaced in the nutritional treatment of SAP. The concept of “staged nutritional support therapy” for SAP has received attention from scholars, which can maintain the integrity of intestinal mucosa, enhance immunity, reduce the occurrence of complications, and be effective for SAP patients. To date, there is no definite conclusion on the best time to start nutritional support therapy for SAP patients, and clinicians must accurately assess the stage and severity of the disease, which may be too early to perform nutritional support therapy and too late to cause malnutrition and metabolic disorders. The idea of implementing nutritional therapy in phases, i.e., gradually transitioning from PN, PN+EN to EN, is a more individualized treatment plan for patients with different needs (if there is a contraindication to EN). IV. Outlook EN is crucial in the treatment of SAP patients, and the timing of starting EN is still controversial at home and abroad. Most domestic scholars advocate that it is safe and feasible to give EN 48-72 h after admission and can achieve good results. A number of recent foreign RCT studies have confirmed that EEN (within 24 h of admission) is safe and effective for SAP patients, with no adverse effects and no risk of aggravation, and that EEN can achieve similar or even better clinical outcomes than EN treatment. In addition, “phased nutritional support” is a more individualized treatment plan, which can meet the treatment needs of different patients. It is recommended to implement EEN as soon as possible when SAP patients have stable vital signs and no obvious contraindications, in order to better alleviate the disease and improve the prognosis.