The sternum bulges forward, which is called pectus carinatum (chickenbreast). Pectus carinatum is a common chest deformity, which is generally believed to be related to heredity. Most people believe that it is caused by the overgrowth of ribs and costal cartilage, and the deformity of the sternum is secondary to the deformity of the ribs. It accounts for about 6% to 22% of chest deformities, and the male:female ratio is about 3:1. Clinically, according to its different anatomical shapes and surgical treatment methods, pectus carinatum is divided into three types, namely keel chest, pouter pigeon breast and lateral breast. Moderate and severe deformities will have adverse effects on the physiological and psychological development of the sick child and should be treated surgically.