The following causes are common in children with prominent sternum: first, rickets, the causes include lack of vitamin D, calcium and phosphorus in the diet, insufficient sunlight exposure resulting in the body’s inability to properly synthesize vitamin D, suffering from digestive system diseases or kidney diseases, resulting in reduced absorption of vitamin D and increased elimination of calcium and phosphorus, clinical manifestations include rooster chest, string rib, occipital baldness, square skull, ping-pong feeling when finger pressure is applied, closure of fontanelle Treatment includes more sun exposure, oral or intramuscular vitamin D supplementation, avoiding excessive weight bearing on the lower limbs to prevent bending deformities, and timely treatment of primary diseases such as renal insufficiency to restore the body’s ability to absorb vitamin D and calcium and phosphorus normally. Second, deformed healing after sternal fracture, fracture of the sternal stalk in children, poor alignment after fracture, deformed healing occurs, which can lead to local abnormal protrusion.