Why do I need a chest strap after flap replacement surgery? What is the best way to tie it? How to control the tightness? How long should it be tied? Most heart valve replacement surgeries are done through a median sternotomy, and the sternum needs to be tied with several wires to restore the continuity and stability of the thorax after the surgery. Due to the presence of osteoporosis in many patients, even the use of wires to secure the sternum does not ensure complete stability. Coupled with other factors, such as postoperative asthma attacks, recurrent lung infections, violent coughing, incorrect coughing patterns, asymmetric force on both arms, excessive weight bearing on the upper extremities, and prematureness, the wires cut the sternum and become loose. Therefore, we also highlight in this article the correct postoperative coughing style and protective movements, as well as getting up and lying down, all of which are cathartics around the protection of the sternum after open-heart surgery. Another important method is the use of a chest immobilization band. The chest strap is designed to limit the movement of the thorax when the patient coughs, moves the upper limbs and other activities, thus reducing the tension between the sternum and the wire and serving to protect the chest incision and especially the sternum. The correct position of the chest strap: the position of the chest strap cannot be too high, too high will be stuck in the patient’s bilateral armpits, the patient will feel very uncomfortable; nor can it be too low, too low will not play a role in fixing the sternum. Generally, the upper edge of the chest strap is close to the axillary fold (when the upper arm is naturally drooping), it is OK. As for the tightness, the patient should have the feeling of tightening when breathing deeply, but it should not affect the breathing, if the patient feels unable to breathe, it is too tight; if the patient does not have the feeling of tightness, it is too loose. The time limit for the use of the chest belt is not absolute, the healing ability of the sternum is related to many factors such as the patient’s age, physical condition, nutrition, whether or not there is diabetes, etc. There is no specific, individualized recommendation, and there is no need. Therefore, we uniformly recommend 3 months of playing. If the patient is older, has severe osteoporosis, has a lot of postoperative sputum, and is heavy, we also recommend that the patient use 2 chest straps, i.e., an additional cloth, less elastic, multiheaded chest strap to enhance sternal protection. When using a chest belt, a cotton, unbuttoned body shirt can be worn underneath. If the body sweats in hot weather, it is more economical and convenient to replace the laundry than to replace the chest belt.