Inclusion Criteria:  Age ≥30 years old, ≤75 years old, no gender limit; Meet the KOA diagnostic criteria in the "Classification Criteria for Knee Osteoarthritis" revised by the American College of Rheumatology (ACR); According to the X-ray K-L grading and evaluation standard, it is at level II-III; Continuous pain for at least 6 months; No local or systemic infection; There is no obvious contraindication for articular cavity puncture in hematology and biochemical testing; Subjects and their families understand the clinical trial protocol and agree to participate in the trial, voluntarily and sign an informed consent form;  Exclusion Criteria:  Age<30 years old; Tumor diseases; Severe kidney, lung or liver damage; Blood diseases include anemia and thrombocytopenia; Type I diabetes; Severe effusion; Contracture or instability of the knee joint, with an axial deformity greater than 10°; Infectious arthritis or skin disease; Inject corticosteroids and immunosuppressants into the knee joint within 2 months; Suffer from mental illness and poor compliance; Cases that the investigator thinks are not suitable for inclusion in the group.