Fluid accumulation in the knee may not be related to postoperative lumbar disc herniation. The treatment of fluid accumulation in the knee should be based on different causes to choose different methods, the common causes are synovitis, gouty arthritis, osteoarthritis and so on, the treatment includes general treatment, medication, physical therapy and so on. 1. Synovitis: reduce joint activities, avoid cold, etc.; microwave therapy and far infrared therapy for knee; oral non-steroidal anti-inflammatory drugs such as celecoxib, etc.; puncture to extract the fluid when there is too much fluid which is not easy to be eliminated. 2. Gouty arthritis: reduce joint movement, local elevation; oral non-steroidal anti-inflammatory drugs, such as ibuprofen, etc., and puncture to extract the fluid when there is too much fluid. 3. Osteoarthritis: timely rest, prevent cold; local acupuncture, physiotherapy, baking electricity, etc.; puncture extraction when there is too much fluid. If there is fluid in the knee after lumbar disc herniation surgery, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor, and do not blindly use medication on your own.