This trial plans to enroll 190 eligible patients and randomize them into two groups with a 1:1 ratio, with 95 patients in each group. The experimental group will receive immediate cryoablation therapy at the resection site after TUR, while the control group will only undergo TUR and receive conventional BCG instillation therapy postoperatively. Both groups of subjects will undergo Re-TURBT or cystoscopy 10-12 weeks after surgery to compare the tumor-free residual rates and adverse events between the two groups.

Inclusion Criteria:

1. Aged between 18 and 85, male or female;
2. Preoperatively diagnosed with T1 stage or meeting the criteria for high-risk bladder cancer (accord with the "2023 NCCN Bladder Cancer Guidelines");
3. Good compliance and able to cooperate with observation;
4. Able to understand the purpose of the trial, agree to participate in this study, and have signed the informed consent form.

Exclusion Criteria:

1. Patients with severe infectious diseases such as bacteremia and toxemia;
2. Patients with severe coagulation dysfunction;
3. Patients with severe heart, brain, lung, liver, kidney and other diseases who cannot tolerate surgery;
4. Patients with other concurrent malignancies;
5. Postoperative pathological diagnosis of bladder cancer patients in Tis, Ta, or T2 stages;
6. Preoperative CT/MRI assessment showing tumor invasion beyond the bladder (T3 stage or above);
7. Preoperative assessment indicating distant metastasis or enlarged pelvic lymph nodes;
8. Pregnant or breastfeeding women;
9. Other situations assessed by researchers as unsuitable for inclusion in this study, such as inappropriate anatomical structure, mental or psychological disorders.