Bladder cancer is a common malignant tumor of the urinary system, radical resection plus urinary diversion is the first choice of treatment for muscle invasive bladder cancer. Urinary diversion of surgical options related to patient'survival and quality of life. In 2000, professor Chunxiao Liu invented detaenial sigmoid neobladder, this surgical method overset the traditional intestinal detubularization approach, which detached the serosal layer with smooth muscle from the bowel without split it. This kind of neobladder is easier to construct and have less impact on intestinal function. So far, it has been implemented for more than 700 cases in Zhujiang hospital, the age of patients range from 9 months (bladder rhabdomyosarcoma) to 88 years old. The filed of standard radical bladder cancer resection includes the structure of the prostate and seminal vesicles. More and more studies and long-term clinical experience in our hospital have confirmed that capsule sparing cystectomy can achieve good tumor control and excellent functional recovery. Our project is going to perform a randomized controlled trial for capsule sparing cystectomy and conventional radical cystoprostatectomy and look forward to assess the oncology outcome and functional recovery of these two procedures which provide an objective basis for the patients undergoing orthotopic urinary diversion in the future.