As the saying goes, every disease has three parts to treat and seven parts to maintain. For patients with osteoarthritis of the knee, prevention and health care are very important. First, to establish the correct knee exercise concept, should avoid sports that aggravate joint injury or symptoms, such as the usual slow walking, jogging, cycling, walking in water and other sports. Avoid hiking, fast and long stair climbing, repeating a strength exercise, and playing competitive sports. Some elderly people think that osteoarthritis of the knee is a long bone spur, as long as a lot of exercise can “wear” the bone spur, this view is wrong, excessive exercise will not wear off the bone spur, but can aggravate the disease, making the pain increased. Some older people think that climbing is a good exercise for the knee joint. Although climbing is a good way to exercise, it is not good for patients who already have osteoarthritis of the knee to protect the knee joint. This is because the knee joint is basically weighted by its own body weight when going up a mountain, and when going down a mountain, the knee joint has to bear the force of the downward stroke in addition to its own weight, which increases the wear and tear on the knee joint. The quadriceps muscle plays a very important role in the knee joint, and a strong quadriceps provides strong protection for the knee joint, so quadriceps exercise is very important for patients with osteoarthritis of the knee. Here we introduce two simple and effective exercises. Prone quadriceps contraction exercise: straighten the knee joint as much as possible, while keeping the knee straight, make the quadriceps contract, each contraction should be insisted on 5 seconds, 20 times as a group, do 3-5 groups per day. Reclining straight leg raise exercise: lying flat on the bed, lower limb muscles tightened, tense, raised so that it is 45 degrees angle with the bed, hold for 5 seconds, and then slowly put down. Repeat this for a group of 20. Do 3-5 sets a day. Next, do a good job of keeping the knee joint warm. Many older people may have the experience that once it rains on a cloudy day or the weather turns cold, the pain in the knee joint will increase. This is because when the weather changes or gets cold, the blood circulation in the knee joint will be affected, resulting in impaired blood supply to the knee joint and a buildup of metabolites, which can aggravate the pain. Keeping the knee joint warm can promote blood circulation in the knee joint and speed up the discharge of metabolites, thus playing a role in protecting the knee joint. Third, obese patients should moderate their diet and reduce their weight. Finally, it is recommended to use a walking stick or hiking stick. This can reduce the pressure on the affected joints, increase stability, improve function, reduce the stress on the joints of the lower limbs and pain when walking, and possibly slow down the degeneration process of the joints.