The reason for the formation of synovial sarcoma is still unclear, mostly related to the living environment, personal diet, chronic injury and other factors. 1. Living environment: if patients live in polluted or harmful environment for a long time, certain uncertain components will continuously stimulate the synovial tissue, leading to cell proliferation and mutation, and finally forming synovial sarcoma. Synovial sarcoma is formed when certain uncertain ingredients continuously stimulate the synovial tissue, leading to cell proliferation and mutation. 2. Personal diet: pesticide and toxin residues on vegetables, fruits and other foods may also irritate the synovial membrane, thus causing synovial sarcoma. 3. Chronic injury: if the synovial membrane has chronic injury, inflammation and other problems, which can not be cured for a long time, it may undergo malignant changes and evolve into synovial sarcoma after being stimulated. The reason for the formation of synovial sarcoma is still not completely clear, it is suggested that patients should go to regular hospitals in time, and follow the diagnosis and treatment advice of specialists to standardize the diagnosis and treatment.