Objective To analyze the clinical value of peripheral blood T lymphocyte subsets combined with urine culture in the diagnosis of urinary tract infection after percutaneous nephrolithotomy (PCNL). Methods A total of 220 patients undergoing PCNL in the hospital were analyzed between January 2012 and December 2019. According to presence or absence of urinary tract infection within 1 month after surgery, they were divided into infection group (48 cases) and non-infection group (172 cases). The clinical data ［age, body mass index (BMI), preoperative white blood cell count, size of stones, preoperative extracorporeal shock wave lithotripsy, medication for stone clearance, hydronephrosis, operation time, postoperative ureteral indwelling time, diabetes, hypertension］ of patients were recorded. At 3d after surgery, urinary bacteria were detected by VITEK 2 Compact. The levels of peripheral blood T lymphocyte subsets (CD3+, CD4+,CD8+,CD4+/CD8+) were detected by flow cytometry. The risk factors affecting postoperative urinary tract infection were analyzed by Logistic regression analysis. The predictive value of T lymphocyte subsets and urine culture for urinary tract infection after PCNL was compared. Results Age, postoperative urinary white blood cells count over 2/HP, preoperative extracorporeal shock wave lithotripsy, hydronephrosis and postoperative long ureteral indwelling time (OR=1.852,P=0.045) were risk factors affecting urinary tract infection after PCNL (P＜0.05). In infection group, there were 44 cases with positive urine culture results and 4 cases with negative. In non-infection group, there were 34 cases with positive urine culture results and 138 cases with negative. The levels of serum CD4+and CD4+/CD8+in infection group were significantly lower than those in non-infection group. AUC values of CD3+, CD4+, CD8+, CD4+/CD8+, urine culture and their combination for predicting urinary tract infection were 0.565, 0.620, 0.531, 0.777, 0.859 and 0.956, respectively. Conclusion Peripheral blood T lymphocyte subsets combined with urine culture are of diagnostic value in urinary tract infection after PCNL.