Background <p>This study attempts to evaluate the clinical performance and safety of a front-end flexible intelligent pressure-control ureteral access sheath (FT-IPC UAS) in retrograde intrarenal surgery (RIRS) for infection-related renal calculi. This research also aims to develop a predictive model for postoperative infection.</p> Methods <p>A total of 124 patients with renal calculi were prospectively enrolled and randomly assigned in a 1:1 ratio to the observation group (FT-IPC UAS) or the control group (conventional sheath). The primary endpoint was the 1-month stone-free rate (SFR). Intraoperative parameters, postoperative recovery outcomes, calculi-free rates, complication rates, and incidence of infection were compared. Logistic regression analysis was adopted to identify independent risk factors for postoperative infection. A multivariable prediction model was constructed and evaluated using receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and the Hosmer–Lemeshow goodness-of-fit test.</p> Results <p>The calculi-free rate was also higher in the observation group, while the infection rate was markedly lower. The observation group demonstrated significantly shorter surgery time, lower peak perfusion pressure, improved surgical field visibility, and declined postoperative inflammatory markers (all <i>p</i> &lt; 0.001). Patients in the observation group experienced faster recovery. Multivariate regression analysis identified procalcitonin (PCT) &gt; 0.5&#xa0;ng/mL as an independent risk factor for postoperative infection. The combined prediction model yielded an AUC of 0.8055, indicating good predictive performance.</p> Conclusions <p>The FT-IPC UAS enhances surgical efficiency, accelerates recovery, and reduces infection risk during RIRS. The predictive model incorporating PCT, sheath type, and surgery time offers reliable guidance for postoperative infection.</p>