Focused low-intensity pulsed ultrasound (FLIPUS), as a non-invasive physical therapy, is widely used in orthopedics, neurosurgery, urology, rehabilitation medicine and other clinical specialties. More and more studies have found that FLIPUS can treat knee osteoarthritis (KOA) by promoting tissue regeneration, relieving pain and inhibiting inflammation, improve the common clinical symptoms of KOA, such as joint pain or stiffness, limited joint activity and decreased walking function, and improve the quality of life of patients to a certain extent. This article mainly reviews the effect and biophysical mechanism of FLIPUS in the treatment of KOA, as well as related clinical research, in order to provide a reference for clinical workers who carry out research in this field.