Knee instability should be treated with progressive muscle training and joint mobility training under the guidance of a professional rehabilitator. 1. Muscle training: Knee instability is related to the weak strength of the surrounding muscle groups, thus strengthening the muscle strength around the knee can help to improve the stability of the knee. Commonly used training are straight leg raise, squatting, etc. You can also borrow elastic bands to do resistance training. 2. Joint mobility training: Meniscus injury, ligament strain, synovitis and other diseases can also lead to knee instability. While treating the primary disease, we should also do knee flexion and extension exercises to avoid long-term braking affecting joint mobility and aggravating knee instability. Knee instability must follow the doctor’s instructions for correct training to improve, to avoid aggravation of the condition affecting normal life.