This study is an ambispective cohort observational study to analyze the efficacy of adjuvant radioimmunotherapy (radiotherapy and immunotherapy) compared with adjuvant chemotherapy in patients with the upper urinary tract urothelial carcinoma with high-risk factors (postoperative pathology suggestive of pT2 and above, N+, G3/high-grade and multiple tumors, positive cut margins). A subgroup analysis was performed to obtain the population of patients who might benefit from different treatment approaches. Patients with high risk factors for postoperative recurrence or metastasis will be treated with relevant adjuvant therapy, which in turn will benefit patients.