Hydronephrosis is mainly caused by urinary tract obstruction, and the treatments include nephrostomy and drainage, lithotripsy, nephrectomy and so on. 1. When the patient’s condition is critical and the obstruction cannot be relieved temporarily or major surgery is not allowed, nephrostomy drainage is feasible, which is helpful for controlling the infection and improving the renal function. 2. When ureteral stone with mild hydronephrosis, shock wave lithotripsy or transureteroscopic lithotripsy is feasible, and according to the intraoperative situation to decide whether it is necessary to place double J tube drainage. 3. Severe hydronephrosis, severe loss of renal function, the contralateral side of the kidney function is good, conditions permit the feasibility of nephrectomy. The treatment of hydronephrosis should be based on the cause of obstruction, severity, complications and renal function damage. It is recommended to actively seek medical treatment as prescribed by the doctor to avoid deterioration of the condition.