The cause of pediatric hip synovitis is not yet clear, and is considered to be related to traumatic injury, intra-articular injury, joint infection, immune disease and other factors. 1. traumatic trauma: for example, direct impact on the hip joint area is likely to cause injury, which in turn produces non-specific pediatric hip synovitis disease. 2. Intra-articular injuries: If a small child’s usual exercise is large, it may cause cumulative damage to the hip joint, which in turn may produce pediatric hip synovitis. 3. Joint infections: Bacterial, tuberculosis, viral infections, etc., may involve the hip joint and cause infectious hip synovitis. 4. Immune diseases: for example, children with ankylosing spondylitis, rheumatoid arthritis and other autoimmune diseases may increase the risk of chronic inflammatory hyperplasia of the synovial membrane of the hip joint, which may lead to the occurrence of pediatric hip synovitis. There may be other causes of pediatric hip synovitis, which should be given high priority and require further examination and treatment with the doctor.