Ureteral malformation is one of the most common urinary system malformations, with more females than males, often bilateral, which can be divided into two types: incomplete and complete. Most of the incomplete ureters have no clinical symptoms, and the complete double ureteral malformation has two ureteral buds, forming two completely independent ureters and renal pelvis. Both ureters lead to the bladder, or one leads to the bladder and the other leads to the urethra or urinary system. Most of them have symptoms of urinary tract infection.