Left rib protrusion in 7-year-old children may be caused by congenital developmental malformation, rickets, costochondritis, etc., and should be treated according to the cause of the disease, including medication and surgical treatment. Congenital deformity of rib development leads to left rib protrusion, if it does not affect the normal function of the body such as respiration, circulation, digestion and so on need not be dealt with, if it affects the quality of life, then it needs to be corrected surgically. Rickets, or vitamin D deficiency rickets, is a disease caused by vitamin D insufficiency, resulting in calcium and phosphorus metabolism disorders, so that the growing epiphysis, cartilage plate can not be normal calcification, which leads to bone lesions. It can be caused by insufficient sunlight and insufficient vitamin D intake. It should be treated with vitamin D supplementation and calcium supplementation, but it has no curative effect on the skeletal deformities that have already formed, and may leave behind skeletal deformities such as O-legs, X-legs, and chicken breasts. Costal chondritis is divided into non-specific costal chondritis and infectious costal chondritis, the most common clinical non-specific costal chondritis, which requires localized hot compresses, physiotherapy, and localized closure of procaine and other treatments. Infectious costochondritis requires antibiotic treatment (e.g., cefradine, etc.). It is recommended to seek medical advice and follow the doctor’s instructions for medication and treatment.