9-year-old children with double knee pain may be due to synovitis, knee injury, growing pains and other factors, generally can take medication, physical therapy, etc., it is recommended to go to the hospital in time to identify the cause of the disease, symptomatic treatment. 1. synovitis: due to the children’s daytime activities, there may be synovitis, mainly manifested as swelling, pain and other symptoms, the child is 9 years old, double knee pain may be caused by synovitis, can be relieved by resting, pay attention to avoid strenuous exercise. 2. Knee joint injury: due to the child’s activities, excessive exercise leads to knee joint injury, thus causing pain. It is recommended to take oral ibuprofen extended-release capsules, erythromycin capsules and other drugs under the guidance of the doctor for treatment. 3. Growing pains: 9-year-old children are in a period of rapid growth and development, bone growth rate is faster, soft tissue and bone tissue growth rate mismatch, so that the knee growth pain phenomenon, it is recommended that under the guidance of a doctor, oral calcium gluconate, Vitamin D calcium chewable tablets and other drugs, to alleviate the symptoms. In addition, you should usually try to avoid excessive exercise, timely supplementation of nutrients, diet should be meat and vegetables, nutritional balance.