Vomiting is common in newborns and can be caused by a variety of reasons, one of which is gastroesophageal reflux (GERD). Gastroesophageal reflux (GER) is a common clinical condition in which gastric contents flow back into the esophagus due to lower esophageal sphincter insufficiency caused by systemic or localized reasons, and can lead to serious complications. The incidence in preterm infants can reach 0.8% to 0.85%. The morbidity is related to the following factors 1, preventing reflux barrier malfunction: the lower esophageal sphincter consists of circular muscle, which maintains a certain tension through neuromuscular action, and has a certain pressure at rest, which closes the lower esophagus and prevents gastric contents from refluxing into the esophagus. Gastroesophageal reflux occurs when this muscle is reduced or functionally defective. 2.Dysfunction of esophageal peristalsis: When food enters the esophagus, a downward peristaltic wave occurs in the esophagus to send the food into the stomach, and when it is dysfunctional, the refluxed gastric contents continue to overflow. 3.Anatomical abnormalities of the esophagus and stomach: such as esophageal hiatal hernia. 4.Hormonal influences: prostaglandins, hyperglycemic hormone, gastric inhibitory polypeptide can reduce the pressure of the lower esophageal sphincter. Gastroesophageal reflux due to acidic gastric reflux, the esophagus is in a long-term acidic environment, esophagitis, esophageal ulcers, esophageal stenosis, reflux inhalation into the trachea can cause recurrent episodes of bronchopneumonia, pulmonary atelectasis, but also can cause choking, sudden death syndrome. Children often present with vomiting, which occurs in more than 90% of children and can occur as early as one week after birth. There may also be weight loss, esophagitis, esophageal erosion or ulceration: restlessness, agitation, refusal to eat, or in severe cases, vomiting blood or blood in the stool, leading to iron deficiency anemia. Aspiration symptoms may follow reflux aspiration: pulmonary comorbidities, choking, choking, apnea, aspiration pneumonia. It is accompanied by psychomotor retardation. Diagnosis can be made by barium esophagography, which is diagnostic if there are more than 3 refluxes in 5 minutes. It can also be diagnosed by esophageal endoscopy and mucosal biopsy, esophageal pH measurement, esophageal manometry, etc. Ultrasound: 90% positive rate of detection, with filling of the lower end of the esophagus. There is liquid flowing back and forth between stomach and esophagus. Treatment is mainly postural 1, light: 1 hour after eating to maintain an upright position. 2.Severe cases: prone position in bed with 30-degree inclination, or supine with 50-degree angle. 3.Diet therapy: small amount of meals, feeding thick milk. 4.Drug therapy: inhibit gastric acid secretion. 5.Surgical therapy: Ineffective conservative for 6 weeks, serious complications, severe esophagitis or constriction formation, as indication for surgery.