Objective To summarize the best available evidence for care of oral mucositis developed after hematopoietic stem cell transplantation in adults. Methods Literature on oral mucositis in the databases of guidelines, BMJ Best Practice, CINAHL, CNKI, Embase, JBI Evidence-based Health Care Center, PubMed, the Cochrane Library, WanFang, etc. ， was retrieved, classified, and appraised by 2 members of the evidence-based team . Then 2 others extracted and summarized the evidence that met JBI quality standards. Results A total of 15 publications were included, namely 1 guideline, 1 evidence summary report, 9 systematic reviews, 1 Meta-analysis, 2 randomized controlled trials, 1 expert consensus report. From the publications, 13 pieces of best evidence on oral mucositis after adult hematopoietic stem cell transplantation were summarized. Conclusion The summarized best evidence on oral mucositis after adult hematopoietic stem cell transplantation could help medical staff to accurately assess patients′ oral cavity, carry out oral health education, timely take preventive measures and correctly treat oral mucositis.