Knee osteoarthritis is a common orthopedic disease with treatment difficulties， which has a high incidence rate in middle-aged and elderly people. Its pathological mechanism has not been fully understood. Current researches have found a strong correlation between obesity， abnormal lipid metabolism， and the occurrence and development of knee osteoarthritis. Synovial fluid of joints contains many metabolites and directly participates in the regulation of intra-articular metabolism， which can directly reflect the local lipid metabolism status of joints. The lipid metabolism profile in the synovial fluid of patients with knee osteoarthritis includes a variety of fatty acids and their related metabolites such as carnitine， acetyl coenzyme A， as well as a variety of phospholipids and adipocytokines such as adiponectin， leptin， and resistin. Among them， lipids such as arachidonic acid， some shortchain saturated fatty acids， and related metabolites may have a bidirectional regulatory function in the development of KOA， which is worthy of in-depth study. In this paper， we review the literature on the characteristics of lipid metabolism in synovial fluid of patients with knee osteoarthritis， with the aim of clarifying the correlation between lipid metabolism in synovial fluid and the occurrence and development of knee osteoarthritis， and providing some new ideas for the prevention and treatment of knee osteoarthritis.