Objective To retrieve and summarize the best evidence of functional exercise in patients on extracorporeal membrane oxygenation (ECMO) therapy, so as to provide a reference for formulating a scientific functional exercise program for these patients. Methods We systematically searched relevant guideline websites, evidence-based databases, websites of relevant associations and academic databases at home and abroad for evidence on functional exercise in patients on ECMO therapy. The search time limit was from the establishment of the database to June 2023. Two researchers trained in evidence-based medicine methodology evaluated the quality of the included literature. Results A total of 12 articles were included, including 2 guidelines, 5 systematic reviews, 3 expert consensus reports, and 2 randomized controlled trials. Finally, a total of 35 pieces of best evidence were extracted from 4 aspects, including preparation in advance, evaluation, exercise implementation and safety monitoring. Conclusion The best evidence summarized can provide the basis for carrying out limb functional exercise for patients on ECMO therapy, so as to provide patients with personalized rehabilitation training programs.