Objective To investigate the efficacy of negative pressure combined ureteroscopy combined with flexible ureteroscopy holmium laser lithotripsy in the treatment of renal calculi or upper ureteral calculi with a maximum diameter of 2-4cm.Methods The data of patients with renal calculi or upper ureteral calculi with a maximum diameter of 2-4cm who were hospitalized inAffiliated Hospital of Youjiang Medical University for Nationalities from March 2023 to March 2024 were collected and divided into observation group(n=40)and control group(n=40).The observation group was treated with negative pressure combined ureteroscopy combined with flexible ureteroscopy for holmium laser lithotripsy,and control group was treated with nephroscope for percutaneous nephrolithotomy(PCNL).The operation time,postoperative hospital stay,changes of blood routine white blood cell(WBC)before and after operation,changes of urine routine WBC before and after operation,postoperative visual analogue score(VAS),one-stage stone clearance rate and postoperative complications were compared between two groups.Results The postoperative hospitalization time and VAS of observation group were significantly lower than those of control group(P＜0.05).There was no significant difference in operation time,stone clearance rate,postoperative blood routine WBC and postoperative urine routine WBC between two groups(P＞0.05).However,the blood routine WBC of two groups after operation was higher than that before operation(P＜0.05).The overall stone clearance rate of two surgical methods was 86.25％,of which the stone clearance rate of observation group was 82.5％,and control group was 90％.There was no significant difference between two groups(P＞0.05).Conclusion It is safe and effective to treat renal calculi;or upper ureteral calculi with a maximum diameter of 2-4cm by negative pressure combined ureteroscopy combined with flexible ureteroscopy holmium laser lithotripsy.It is expected to partially replace PCNL and become another safe and reliable operation for the treatment of renal calculi or upper ureteral calculi with a maximum diameter of 2-4cm.