Objective:To explore the clinical curative effect and safety of disposable flexible ureteroscopic lithotripsy (FURL) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) in upper urinary tract calculi.Methods:According to random number table method, 68 patients with upper urinary tract calculi were divided into observation group (34 cases,disposable FURL combiend with FV-UAS) and control group (34 cases,traditional reusable flexible endoscope combined with common sheath) between January 2023 and December 2024.The perioperative indexes (operation time,intraoperative blood loss),stone clearance rates at 1 month after surgery and scores of visual analogue scale (VAS) at 24h after surgery in the two groups were observed.The levels of serum interleukin-6 (IL-6) and tumor necrosis factor -α (TNF-α) were detected before and at 1d after surgery,and the incidence of complications (infection,hematuria,ureteral injury) was statistically analyzed.Results:The operation time in observation group was shorter than that in control group [(58.65±7.25) min vs (72.33±8.53) min,P<0.05],and intraoperative blood loss was less than that in control group [(12.52±4.12) mL vs (25.74±6.34) mL,P<0.05].At 1 month after surgery,CT reexamination showed that stone clearance rate (SFR) in observation group was higher than that in control group [94.12% (32/34) vs 82.35% 28/34, χ2=4.353, P<0.05].VAS score in observation group was lower than that in control group (P<0.05).After surgery,levels of IL-6 and TNF-α were increased in both groups,which were lower in observation group than control group (P<0.05).The incidence of complications in observation group was lower than that in control group [5.88% (2/34) vs 23.53% (8/34), χ2= 4.221, P<0.05].Conclusion: Disposable FURL combiend with FV-UAS can shorten operation time,reduce trauma,increase stone clearance rate and alleviate postoperative inflammatory response in upper urinary tract calculi,with better safety.