Objective To search and select the evidence on oral nutritional supplements in perioperative patients,and to summarize the latest and best evidence. Methods We retrieved the UpToDate,BMJ Best practice,International Practice Guideline Registry Platform,National Institute for Health and Care Excellence (NICE),Guidelines International Network(GIN),Registered Nurses Association of Ontario(RNAO),Scottish Intercollegiate Guidelines Network(SIGN),European Society for Clinical Nutrition and Metabolism(ESPEN),American Society for Parenteral and Enteral Nutrition(ASPEN),Joanna Briggs Institution(JBI),Cochrane Library,Pubmed and CBM,and collected relevant guidelines,clinical decisions,evidence summaries,systematic reviews and expert consensuses. 2 researchers independently evaluated the quality of the included literature,and extracted and summarized the evidence from the included literature. Results Finally,14 articles were included in this summary,including 2 guidelines,2 clinical decisions,6 expert consensuses and 4 systematic reviews. 16 pieces of latest and best evidence were summarized,including indications,recommended dosage,health education,preoperative nutrition,postoperative nutrition,bariatric surgery and post-discharge nutrition. Conclusion The study summarized the latest and best evidence of oral nutrition supplements in perioperative patients,and provided evidence-based nutritional interventions for malnutrition perioperative patients,which may improve the nutritional status and postoperative clinical outcomes and ensure the security of patients.