The normal kidney position is that the kidney door is equivalent to the first and second lumbar transverse processes, and the right side is slightly lower than the left side. In the standing position, the kidney can descend 2-5cm, which is equivalent to one vertebra, beyond this range, it is called renal prolapse. In a few patients, the kidney is wrapped by the peritoneum and the kidney tip is loose, so it can move in the abdominal area, some even descend into the lower abdomen or pelvis, or cross the midline to the opposite side of the abdomen, this kind of kidney prolapse is called wandering kidney, generally seen on the right side. The main symptoms: back pain, due to the bending of the ureter can lead to hydronephrosis or upper urinary tract infection. It is often complicated by renal hypoplasia, renal malrotation, renal vascular malformation and ureteral overgrowth and other abnormalities. Etiology: The etiology is mostly due to the formation of the kidney in the embryonic period due to the influence of the renal blood vessels in the abnormal area, which cannot reach the normal position, generally the pelvic ectopic kidney is more common, transverse ectopic kidney and thoracic ectopic kidney are rare.