The diagnosis of bladder cancer is comprehensive and can be made through clinical manifestations, urine examination, imaging examination, cystoscopy and biopsy. 1. Clinical manifestations: the most common symptom is hematuria, mostly intermittent painless hematuria throughout, which can be reduced or disappeared by itself, as well as symptoms of frequent urination, urgency of urination, pain in lumbosacral region, edema of lower limbs and weight loss. 2. Urine examination: routine urine examination should be alert to the possibility of bladder cancer when the red blood cell count is >5/high magnification field of vision repeatedly, and urine bladder tumor antigen, nuclear matrix protein and other examinations can help early diagnosis of bladder cancer. 3. Imaging examination: color ultrasound can be used as the initial screening of patients, and intravenous pyelography and CT reconstruction of the urinary tract can be used to know whether there are tumors in the renal pelvis and ureter. 4. Cystoscopy: cystoscopy is the most reliable method to diagnose bladder cancer, which can observe the location, number and size of tumor under direct vision, as well as perform biopsy. 5. Biopsy: The pathological result of biopsy is the gold standard for diagnosing bladder cancer, and pathological tissues can be taken through cystoscopy. If bladder tumor is suspected or diagnosed, it is recommended to go to regular hospitals for comprehensive assessment of the condition, follow the doctor’s instructions to cooperate with the treatment, and choose the appropriate treatment plan to avoid delaying the condition.