Bladder cancer mostly occurs in middle-aged and elderly people over 50 years old, and the incidence rate increases accordingly with age. The occurrence of bladder cancer is closely related to diet, smoking and drinking water, so the prevention of bladder cancer should also start from the source: 1. eat more fresh vegetables and fruits; 2. quit smoking; 3. increase water consumption; 4. carry out mass census, especially for the high-risk group; 5. Improve the production conditions of dyestuff, rubber, leather and other industries to prevent bladder cancer by avoiding massive and long-term consumption of cancer-causing drugs; 6. Pay great attention to the close follow-up of patients with hematuria, especially for unexplained carnal hematuria in men over 50 years old, strict measures should be taken in principle to prevent the occurrence of bladder cancer.