After 10 weeks of embryonic life, the midgut is returned to the abdominal cavity from the umbilical cavity to form a normal distribution in the abdominal cavity. Insufficient rotation or reverse rotation of the midgut when it is returned to the abdominal cavity results in congenital malrotation. Congenital dysplasia includes a series of lesions such as duodenal tethering compression, abnormal midgut position and intestinal rotation. Clinical manifestations: intestinal obstruction is the main clinical manifestation of congenital dysphonia. Some children are asymptomatic due to the absence of intestinal obstruction. Duodenal obstruction can be incomplete or complete. Children often have congenital pulmonary and cardiovascular malformations. Complete intestinal obstruction occurs mostly in the neonatal period and is a common cause of neonatal intestinal obstruction. Bilious vomiting occurs 3-5 days after birth. Most of the children have growth lag and no or decreased weight gain. Intestinal torsion leads to mesenteric vascular obstruction, and intestinal ischemic necrosis, intestinal perforation and peritonitis may occur. Ultrasound manifestations: The ultrasound manifestations of congenital intestinal malrotation mainly include intestinal obstruction and intestinal torsion. In the case of duodenal obstruction in the descending, transverse or upper jejunum, the sonogram shows fluid accumulation and dilatation in the stomach and duodenum with gastroesophageal reflux. In addition to the sonographic manifestations of intestinal obstruction, intestinal torsion can show a mixed abdominal mass located below the pancreas with varying degrees of mesenteric vascular abnormalities. The superior mesenteric artery and the superior mesenteric vein may show different degrees of abnormal position. The masses of intestinal torsion are formed by the coiled intestinal tube and mesentery, with a coiled or spiral moderate echogenicity in the sonogram, mostly in the upper abdomen, and color Doppler shows the mesenteric vessels in a coiled pattern. The location of normal mesenteric vessels is that the superior mesenteric vein is located to the right of the superior mesenteric artery and extends side-by-side to the right lower abdomen. In malrotation, the vascular pathway is abnormal in that the mesenteric vessels are crossed and the superior mesenteric artery is located to the right of the superior mesenteric vein and extends towards the right upper abdomen, so that the longitudinal view of the transabdominal aorta or inferior vena cava does not show the mesenteric vessels. Congenital malrotation of the intestine is often complicated by intestinal duplication malformation and Meckel’s diverticulum. Ultrasound shows a thick-walled cystic mass of the intestinal canal. Congenital malrotation and intestinal torsion are also common in children with visceral ectopic syndrome and congenital heart disease, for which ultrasonography of the liver, spleen, and heart should be performed.