Objective To search,evaluate and integrate the best evidence for preoperative fasting management in patients undergoing elective general anesthesia. Methods PubMed, Cochrane Library, BMJ Best Practice,Geenmedical, NGC, GIN, CMA Infobase, NICE, UpToDate, CBMdisc, CKNI,Wanfang,Clinical guidelines,ASA,Chinese Society of Anesthesiology,European Society of Anesthesiology,and ERAS were searched for evidence of preoperative fasting from database establishment to June 2021. The quality of the included articles was evaluated by 2 investigators,and the evidence was extracted and integrated. Results A total of 20 articles were included in this study,including 10 guidelines,1 evidence summary,4 systematic reviews,1 cross-sectional study,2 expert consensuses and 2 randomized controlled trials,which summarized 17 pieces of evidence involving 4 categories,namely gastric emptying mechanism,risk assessment,fasting protocol,education and training. Conclusion This study summarizes the best evidence of preoperative fasting management in patients undergoing elective general anesthesia,and suggests that medical staff should carry out preoperative comprehensive evaluation under the premise of understanding the mechanism of gastric emptying,and develop preoperative fasting protocols in multidisciplinary collaboration to improve the quality of medical care.