Inclusion Criteria:  Patients with a confirmed diagnosis of high-risk NMIBC at each study center:  including (1) inadequate first TURBT; (2) absence of muscle tissue in the first TURBT specimen, except for TaG1 and carcinoma in situ alone; (3) stage T1 tumors; (4) grade G3 tumors, except for carcinoma in situ alone; (5) TaG1G2 meeting both multiple, recurrent, and >3 cm in diameter (or low-grade urothelial epithelial carcinoma)  gender is not limited. age ≥ 18 years old. the ability to provide a 100 ml standing urine sample within 3-6 weeks after the first TURBT and before the secondary transurethral resection. agree to provide basic personal clinical information and pathological and imaging data for use in scientific research and sign an informed consent form related to scientific research. consent to perform the genetic testing services involved in the trial. agree to provide monitoring results in the follow-up relapse monitoring process.  Exclusion Criteria:  patients with other non-uroepithelial malignancies (including prostate cancer and renal cell carcinoma). patients who failed to undergo secondary transurethral resection. patients with incomplete information on sample pathology. patients with contaminated samples. Patients whose urine samples fail quality control and cannot be re-sampled for valid reasons. Patients whose samples cannot complete the test due to reasonable cause. any condition that, in the opinion of the investigator, may harm the subject or cause the subject to be unable to meet or perform the requirements of the study. Patients who are unable to provide written informed consent.