Pediatric duplicated kidney duplicated ureteral malformation is one of the common urological malformations, which clinically often causes urinary tract infection, recurrent fever, hydronephrosis and wet pants incontinence, etc. Previously, nephrectomy was often used to treat the disease with large wounds and injuries. With the development of technology, we now routinely use laparoscopic minimally invasive methods to replace the previous open surgery and reduce the damage to the child, but regardless of the open or laparoscopic minimally invasive techniques, heavy nephrectomy is a relatively large operation. Moreover, not all heavy kidneys need to be removed, some of them still have the value of preservation. For these patients with heavy kidneys that can be preserved, what kind of surgery has less damage and better results? In our patients with partially functional heavy kidney, it is clear that the lower pole ureter has no ectopic opening and/or ureteral cysts, an inguinal skin incision of about 1.5-2.0 cm is made, the distal end of the upper pole ureter is removed, the proximal ureter is cut and laterally anastomosed with the lower pole ureter, and a double J tube is placed in January. The surgery was minimally invasive, aesthetically pleasing, with good results, and was well received by the parents.