Objective To retrieve, evaluate and summarize the best available evidence for assessment and selection of vascular access devices (VADs) in ICU adult patients. Methods The evidence-based problem was established according to PIPOST, then relevant clinical decisions,guidelines,expert consensus,evidence summaries,recommended practices, systematic reviews,meta-analyses and original articles on assessment and suitability selection of VADs in ICU adult patients were systematically searched based on the "6S" evidence model. The search time frame was from June 1st, 2018 to June 1st,2023. Two researchers who completed evidence-based nursing training independently evaluated and performed evidence extraction. Results A total of 14 articles were included, consisting of 3 clinical decisions,1 evidence summary, 4 guidelines, 4 expert consensus reports and 2 randomized controlled trials. Totally 34 pieces of evidence were summarized and factored into 9 themes. Conclusion The best evidence on assessment and selection of VADs in ICU adult patients can provide references for clinical decision of medical staff, while the clinical context is complex and diverse, so the selection strategy should be adjusted according to patient′s condition.