In the past year, a group of infants and toddlers (the youngest is only one month old) have been treated with open surgery through small incisions in the Department of Urology and Surgery of our hospital for congenital hydronephrosis, and the purpose of relieving obstruction and protecting kidney function has been achieved after the surgery. The introduction and implementation of this new technique in the Department of Urology of our hospital has filled the gap in this area in our city. It will benefit more children. Congenital hydronephrosis is a relatively common disease in pediatric patients, with 1 in 600-800 births. With the updated view of eugenics and the popularity of prenatal checkups, more and more congenital hydronephrosis is detected during maternal pregnancy or neonatal period. Unlike the past when it was detected when the child was several years old. This requires doctors to have the means to reliably and effectively treat the condition in young babies. This disease is ineffective with medication, and the problem has to be solved surgically. The traditional and classical surgical approach at home and abroad is Anderson-Hynes, which involves making a large incision (8-10 cm) from the abdomen into the abdominal cavity or retroperitoneal space for operation, characterized by adequate exposure, ease of operation, reliable surgical quality, few postoperative complications and few opportunities for reoperation, with the disadvantage that the incision is large and leaves a large scar after healing, which is not very aesthetic. The other method is the minimally invasive laparoscopic surgery developed over the years, which is performed through several small keyhole-sized incisions in the abdominal wall, which is aesthetically pleasing after healing and more suitable for older children. For infants and young children, especially small babies within 1 year of age, the operation is more difficult and the postoperative success rate is difficult to guarantee, i.e., the purpose of relieving obstruction and unobstructing the upper urinary tract may not be achieved. Or if one pursues laparoscopic surgery, one may put the cart before the horse. It is characterized by high technical requirements, a small incision of 2-3 cm at the lumbar level, careful operation under direct vision, fine anastomosis of the renal pelvis ureter, little bleeding (no more than laboratory blood sampling), and extraperitoneal, little interference with the gastrointestinal tract, early postoperative feeding to avoid the suffering of the child’s hunger, reliable postoperative results, and beautiful, hidden incisions ( Most of them are not in the front but in the back of the side). This is also a minimally invasive and precise surgical technique to treat hydrocele, which is popular among parents because it meets the aesthetic requirements while satisfying the clinical treatment results.