Objective:To investigate the effects of different types of flexible ureteroscope on upper urinary calculi and the related factors of complicated urinary sepsis. Methods: Two hundred and eighty patients with upper urinary calculi admitted to Shanghai Qingpu Hospital of Traditional Chines Medicine were divided into the study group and the control group according to the difference ofsurgical methods, 140 cases in each group. The study group was treated with digital flexible ureteroscope and the control group was treated with fiberoptic flexible ureteroscope. The operation time, hospital stay, primary stone clearance rate, and postoperative systemic inflammatory response syndrome (SIRS) were compared between the two groups. Results: The operation time and the clearance rate of primary stone in the study group were significantly better than those in the control group (P<0.05). There was no significant difference in the hospitalization time and the incidence of postoperative SIRS between the two groups (P>0.05). The univariate analysis found that the factors associated with ureteroscopy complicated by urinary sepsis included gender, calculus CT value>1 000 HU, urine culture positive, diabetes and operative time (P<0.05). The Logistic regression analysis showed that femininity, calculus CT value>1 000 HU, urine culture positive, diabetes and operation time (>60 min) were independent risk factors for urinogenic sepsis after ureteroscopy soft surgery in patients with upper urinary calculi (P<0.05). Conclusions: The efficacy of digital flexible ureteroscope in the treatment of upper urinary calculi is more significant. At the same time, the patients with the independent risk factors for urinary sepsis after upper urinary calculi soft surgery are the monitoringfocus in the future clinical work.