The occurrence of bladder tumor is a complex, multifactorial and multi-step pathological change process, which has both intrinsic genetic factors and extrinsic environmental factors. Smoking is the most certain risk factor for bladder tumor, about 30% to 50% of bladder tumors are caused by smoking, smoking can increase the risk rate of bladder tumor by 2 to 4 times, and the risk rate is proportional to the intensity and time of smoking. Occupational factors are the earliest known risk factors for bladder tumors. About 20% of bladder tumors are caused by occupational factors, including those engaged in textile, dye manufacturing, rubber chemistry, pharmaceutical and pesticide production, paint, leather and aluminum, iron and steel production. Diesel exhaust accumulation can also increase the risk of bladder tumors. Other possible causative factors include chronic infections (bacterial, schistosomal and HPV infections, etc.), application of the chemotherapeutic drug cyclophosphamide (incubation period 6 to 13 years), abuse of painkillers containing finasteride (more than 10 years), pelvic radiotherapy, long-term consumption of water with high arsenic content and chlorine disinfected water, coffee, artificial sweeteners and hair dyes. In addition, bladder tumors may also be genetically related, with a significantly increased risk of bladder tumors in those with a family history and a significantly higher incidence of bladder tumors in patients with hereditary retinoblastoma. For muscle-infiltrating bladder tumors, chronic urinary tract infection, residual urine and long-term foreign body irritation (indwelling catheter, stones) are closely related, which are mainly seen in squamous cell carcinoma and adenocarcinoma.