Objective:To investigate the efficacy of thulium laser combined with tip-bendable suction ureteral access sheath in the treatment of 1～3 cm kidney stones,and analyze the risk factors for postoperative infection.Methods:A retrospective analysis was conducted on the data of 156 patients with 1～3 cm kidney stones,including an observation group(n=76,treated with thulium laser combined with tip-bendable suction ureteral access sheath)and a control group(n=80,treated with thulium laser combined with tradi-tional negative pressure sheath).The perioperative indicators and stone clearance rate(SFR)of the two groups of patients were com-pared and analyzed to explore the risk factors for postoperative infection.Results:Compared with the control group,the observation group had shorter surgery time,higher postoperative 1-day SFR,and lower incidence of postoperative complications(P＜0.05),while there was no difference in hospitalization days and postoperative 1-month SFR(P＞0.05).Both groups showed an increase in white blood cells,procalcitonin,and interleukin-6 after surgery(P＜0.05),but the observation group was lower than the control group(P＜0.05).Multiple Logistic regression showed that surgical time,stone size＞2 cm,and residual stone size on the first day after surgery were independent risk factors for postoperative infection(P＜0.05).Conclusion:The use of thulium laser combined with a tip-flexible terminal suction ureteral access sheath can improve short-term SFR,reduce surgical time,and have fewer postoperative complications.Surgical time,stones larger than 2 cm,and residual stones on the first day after surgery are independent risk factors for postoperative in-fection.