In recent years, with the improvement of people’s living standards and the widespread development of mass fitness sports, many people have chosen swimming as a sport. However, it is not always clear to many people that swimming is actually a rehabilitation therapy and a good treatment technique for many patients who need rehabilitation. Aquatic exercise, also called hydrotherapy, is a full-body exercise that enhances the patient’s motor skills and coordination. In addition, the recreational aspect of water is better than other sports and has a sense of novelty, thus inspiring self-confidence and uplifting the patient’s spirit, and promoting the early achievement of rehabilitation goals. Knee osteoarthritis is a common joint disease in China, mainly manifested by knee pain, enlargement and deformation, stiffness, pressure pain, bone friction sound, and limitation of movement. Walking training in water has a very good therapeutic effect on it, the human body weight in the water is only 10% of the land, under the action of buoyancy can reduce joint compression and reduce pain, so that the muscles are more relaxed, easy to carry out aerobic training, and reduce the risk of standing and walking training; walking in the water, the resistance than air, the use of this feature can increase the difficulty of resistance training; the water Pressure can promote the elimination of leg swelling; warm water energy on the knee joint will also produce a good thermal therapy effect. Frozen shoulder is also a common joint disease in China. When the body is immersed in water, the activity is easier to complete, which is conducive to the functional exercise of the shoulder joints and limbs. At the same time, the water can play a passive massage, swelling, pain relief effect. Swimming in the water with both arms for paddling and hitting action is coordinated by the shoulder and elbow joints as well as multiple related muscles in the chest and back, which can significantly enhance the muscle strength around the shoulder joint and both upper limbs. For stroke patients using underwater rehabilitation therapy, with the help of water buoyancy, reduce the difficulty of early training exercises, and can use the warm effect of water to promote blood circulation in the limbs, reduce blood viscosity, which is conducive to muscle activity. Health exercises for pregnant women are beneficial during pregnancy and childbirth, but due to the special nature of pregnant women themselves, most exercises are not suitable for pregnant women. In developed countries in Europe and the United States, water exercise for pregnant women has been used as a new form of exercise, through swimming, walking in water, water gymnastics, water skiing and other ways conducive to smooth delivery; in the psychological aspect, pregnant women often swim, can improve the mood, distraction, reduce pregnancy reaction; help pregnant women to maintain a fit body, the body shape recovery after delivery is beneficial, but need to take into account the safety of pregnant women. Because of the gravity of the water on the chest and abdomen, increased breathing resistance to chronic respiratory diseases, especially bronchial asthma, exercise in the water than on land has less likely to cause exercise-induced asthma, hyperventilation and other adverse reactions. However, water sports still need to pay attention to places, such as the elderly and children should be mainly warm water, careful to use cold water and too hot water; each water sports before the preparation activities, not in the case of extreme fatigue and hunger; sports to have professional supervision; sports to do a good job after the treatment, such as drying the water left in the skin. In addition, cardiopulmonary failure and certain mental illnesses are generally not suitable for hydrotherapy. Compared with other countries, China’s aquatic exercise therapy is still relatively late, people’s awareness is not in place and other shortcomings. It is believed that with the progress of research and application, more people will recognize the superiority and convenience of aquatic exercise therapy, and aquatic exercise therapy will have a broader utilization space in the future.