Knee osteoarthritis (KOA) is a common chronic degenerative osteoarthritic disease with a high incidence especially among middle-aged and elderly people, and patients with KOA usually suffer from joint pain and dyskinesia, which is disabling and seriously affects their quality of life. Acupotomy therapy, as one of the characteristic treatments of traditional Chinese medicine, has been proven to significantly reduce the pain of KOA patients and effectively slow down the rapid deterioration of the disease. Therefore, this article reviews the pathogenic factors of KOA and explores the mechanism of action of acupotomy therapy for KOA from the perspectives of mechanical structure, level of inflammatory factors, cartilage repair, and cellular autophagy and apoptosis, in order to provide a more solid theoretical basis and therapeutic strategy for the application of acupotomy therapy in the clinical practice of KOA.