In children, due to developmental reasons, the stomach body is mostly said to be in transverse position, and at the same time, the cardia is not well developed, making it easy for symptoms such as overflow and vomiting to occur, most of which can gradually improve and disappear as they grow older. However, if the child’s vomiting (spitting up milk) becomes more and more severe and the child gradually loses weight, he or she must be alert to congenital hypertrophic pyloric stenosis. Congenital hypertrophic pyloric stenosis is a common disease in the neonatal period. The main manifestations are: 1. vomiting. Beginning 2-3 weeks after birth, gradually aggravated, jet-like vomiting, milk can be ejected from the mouth and nose. The vomit is milk and does not contain yellow-green bile-like fluid. 2, wasting. As vomiting increases, the child does not gain weight, loses weight, urinates less and has fewer stools. The wasting is obvious, the skin is loose, and the spirit is poor. In severe cases, breathing is shallow and slow, and those with moderate malnutrition can die. Tests that need to be done: 1. Abdominal ultrasound. It can reflect the size of the pylorus, the thickness of the muscular layer, the length of the pyloric duct, etc. 2.Upper gastrointestinal tract angiography. It is less used at present, but still has some significance for cases that cannot be determined by ultrasound. Treatment: 1.Surgical treatment. Perform pyloric cricothyrotomy, the effect is satisfactory, safe and reliable. At present, our hospital carries out laparoscopic pyloromyotomy, which is less traumatic, with good results and fast recovery. 2.Supportive treatment. Rehydration is needed before surgery to correct the disorder of water and electrolyte acid-base balance in the body and create good conditions for surgery.