Prostate cancer is the most common male cancer in global, which accounts for 19% of the total and poses great hazards to male health. Unfavorable factors including prostatic specific antigen (PSA) >20 ng/ml, Gleason score >8, and T3/4 are significantly associated with biological recurrence, metastatic progression and poor survival in prostate cancer. In clinical T4(cT4) prostate cancer with bladder invasion patients, symptoms of hematuria, urinary urgency, bladder outlet and ureteral obstruction, and pelvic pain led to a poor quality of life. Radical prostatectomy is crucial for the multimodal treatment of prostate cancer, but limited proof demonstrated enough advantages of the surgery in T4 tumor with bladder invasion. Radical prostatectomy could hardly meet both demands of local tumor control and urinary function. Treatment trends suggest that patients with T4 prostate cancer be treated with radiotherapy combined with androgen deprivation therapy (ADT). However, surgery enables a full pathological assessment of the tumor characteristics and thus a better estimation of the risk of recurrence. Cystoprostatectomy offers an option of surgical treatment for T4 prostate cancer with bladder invasion，which can well remove the bladder and urethra, decrease the risk of positive surgical margins and avoid urination complications. There is no consensus regarding optimal treatment of T4 prostate cancer and no evidence of oncological outcomes of cystoprostatectomy from clinical trials. A randomized clinical trial comparing two multimodal treatment regimens of cystoprostatectomy and radiotherapy for T4 prostate cancer with bladder invasion is therefore warranted.