Objective To evaluate the clinical efficacy of antegrade flexible ureteroscopy in treating special types of middle and lower ureteral obstruction. Methods From January 2024 to May 2026, clinical data of 20 patients with special types of middle and lower ureteral obstruction admitted to Guangdong Provincial Hospital of Integrated Traditional Chinese and Western Medicine were analyzed. The operation time, preoperative and postoperative hemoglobin levels, hydronephrosis, and follow-up conditions of the patients were analyzed. Results All patients underwent successful single-stage surgery, with an average operative time of (75.5 ± 16.4) minutes. There was a significant difference in hemoglobin levels between preoperatively and on the first postoperative day (t = 6.141, P < 0.05). Hydronephrosis on the affected side showed marked improvement when comparing preoperative and one-month postoperative conditions (t = 3.937, P < 0.05). Conclusions Antegrade flexible ureteroscopy via percutaneous nephrostomy tract is a minimally invasive, safe, effective, and well-tolerated approach for treating special types of middle and lower ureteral obstruction, with few complications and rapid postoperative recovery, making it worthy of clinical promotion and application.