Knee osteoarthritis(KOA) is a chronic degenerative disease with cartilage degeneration and destruction and subchondral bone changes as the main lesions, and its pathogenesis is not clear. The two affect each other, resulting in imbalance of tendons and bones, that is,“tendons are not soft and bones are not correct”. The theory of“tendons and bones are correct” describes the synergy between tendons and bones to maintain the function of the knee joint. The“liver governs tendons” and“kidney governs bones” suggest the close connection between tendons, bones and liver and kidney. Based on the theory of“tendons and bones”, this paper discusses that the basic pathogenesis of KOA is liver and kidney deficiency, blood stasis and stagnation, and the nature of the disease is a deficiency of the original and the symptoms are real. It was further concluded that herbs for tonifying the kidney and invigorating blood can inhibit apoptosis and degradation of extracellular matrix, promote chondrocyte proliferation and mesenchymal stem cell chondrogenic differentiation and homing, and improve peri-knee blood supply, in order to provide new ideas for clinical prevention and treatment of KOA.