Knee osteoarthritis (KOA) is a disease based on degenerative pathological changes. Most commonly seen in the elderly and is one of Kenn's leading causes, its symptoms include swollen knees, pain in walking up and downstairs. If left untreated, it can lead to joint deformity and disability. Many clinical studies have reported that abdominal acupuncture has a good effect on KOA treatment, but there is no relevant systematic review. So the purpose of this study is to evaluate the effectiveness and safety of abdominal acupuncture in treating KOA. The following 8 electronic databases will be searched, including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Web of Science, Chinese Scientific Journal Database (VIP), Wanfang Database, and Chinese Biomedical Literatures Database (CBM) from their inception to November 1, 2020 without any restrictions. Researchers retrieve the literature and extracted the data, evaluation of research methods, quality of literature. The outcomes will include a Visual Analogue Scale. The Western Ontario and McMaster Universities Osteoarthritis Index, total effective rate, incidence of any adverse events. We use the Cochrane Risk of a bias assessment tool to evaluate methodological qualities. Data synthesis will be completed by RevMan 5.3.0. We will show the results of this study in a peer-reviewed journal. This meta-analysis will provide reliable evidence for abdominal acupuncture treatment of KOA. INPLASY2020110020. Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.