Adults, especially those above 40 years old, who have painless hematuria, especially terminal hematuria, should think of urinary tract tumor, and the first thing to consider is the possibility of bladder tumor. If the bladder tumor does not invade the muscular layer, this test is often negative. If the mass can be palpated, it indicates that the cancer infiltration is deep and the lesion is advanced. The following tests can help to screen or make a definite diagnosis: 1. Urine routine: if there is prolonged microscopic hematuria and the phase contrast microscopic analysis indicates that the hematuria originates from the lower urinary tract, one should be alert to the occurrence of bladder tumor. Since the hematuria caused by bladder tumor can be intermittent, one to two normal urine routine cannot exclude bladder cancer. 2.Urine cytology (UC) is an important test for bladder cancer, especially for detecting high-grade tumors (including Cis). Increased cell volume, increased nucleus-to-cytoplasm ratio, nuclear pleomorphism, deep staining and irregularity of nuclei, and nucleoli protrusion are characteristic of high-grade bladder cancer. In order to prevent autolysis of tumor cells and increase the positive rate, urine is usually examined for 3 consecutive days, and urine specimens should be sent for examination in a timely manner after being collected. However, the former is non-invasive and convenient to obtain material; the latter is invasive, but more tumor cells can be obtained and the cells are better preserved. The sensitivity of urine cytology for high-grade tumors is 60% to 90%, and the specificity is 90% to 100%. The sensitivity for low-grade tumors is only 30% to 60%, but the specificity is still above 85%. In general, the sensitivity of urine cytology increases with the increase of cellular grade and clinical stage of bladder cancer. Urine cytology examination is especially important for the diagnosis of Cis, because Cis cancer cells are poorly adherent and easy to fall off, which is not easily detected by cystoscopy. 3.tumor marker detection: The ideal tumor marker detection should have good sensitivity and specificity, and the detection should be quick, easy to operate and inexpensive. Although there are many literature reports that tumor markers in urine can be used to diagnose bladder cancer, there is not enough clinical information to prove that these markers can replace the role of cystoscopy in the diagnosis of bladder tumor. Nevertheless, they still have a wide application space in clinical practice with the advantages of being fast, easy, non-invasive and more sensitive. 4.Cystoscopy: Cystoscopy is decisive for diagnosis. Cystoscopy should include the entire urethra and bladder, and the bladder should be slowly filled while observing, and the bladder wall protrusions should be distinguished from real lesions or mucosal folds. In most cases, the site, size, number and relationship to the ureteral opening and urethral orifice can be seen directly, and biopsies can be taken near and away from the tumor to understand whether there is epithelial metaplasia or carcinoma in situ, which is an important step in deciding the treatment plan and prognosis. The biopsy should be taken from both the root and the top of the tumor and sent to the pathology separately, because the malignancy of the top tissue is generally higher than that of the root. If no tumor is seen, the bladder will be flushed repeatedly and the flushing fluid will be collected and sent for cytological examination together with the self-absorbed urine before the examination. 5.Ultrasound examination: Ultrasound examination can clearly show the location, number, size, shape and basal width of tumor under moderate bladder filling, and it can distinguish bladder tumor above 0.5cm, and also detect whether there is fluid expansion in the upper urinary tract. Among them, TABUS is the most convenient, rapid, painless and can be repeated many times within a short period of time, and is the preferred method for preoperative diagnosis, staging and postoperative review of bladder cancer, but TRUS and TUUS can show the bladder cancer site and infiltration degree more clearly and can perform more accurate staging of bladder cancer. More accurate staging of bladder cancer can be performed. 6.X-ray: KUB plain film cannot be used for the diagnosis of bladder tumor, but it can be used to understand the presence or absence of concomitant urinary stones. Intravenous pyelogram (IVU) can understand whether there are tumors occurring in the upper urinary tract at the same time, and filling defects in the bladder can be seen in larger bladder tumors. 7.CT: CT examination has high density resolution and can clearly show bladder tumors of more than 1 cm. 8.MRI: The diagnostic principle of MRI is the same as CT. 9.5-aminolevulinic acid fluorescence cystoscopy (PDD): 5-aminolevulinic acid (5-ALA) fluorescence cystoscopy is performed by instilling 5-ALA into the bladder to produce fluorescent material specifically accumulating in tumor cells, which produces intense red fluorescence under laser excitation, contrasting with the blue fluorescence of normal bladder mucosa, and can detect small tumors that are difficult to be found by ordinary cystoscopy The detection rate can be increased by 20% to 25% for atypical hyperplasia or carcinoma in situ. Injury, infection, chemical or radioactive cystitis, scar tissue, etc. can lead to false positive results for this test. 10.Diagnostic transurethral resection: Diagnostic transurethral resection (TUR) has been gradually adopted as the preferred method to diagnose bladder cancer. If imaging examination reveals tumor lesions in the bladder and there is no obvious sign of bladder muscle infiltration, cystoscopy can be omitted at discretion and diagnostic TUR can be performed directly under anesthesia, which can achieve two purposes: firstly, resection of tumor, and secondly, histological examination of tumor specimens to clarify pathological diagnosis, tumor grading and staging, and provide basis for further treatment and prognosis. If the tumor is small, the tumor can be removed together with its basal bladder wall and sent for pathological examination; if the tumor is large, the surface part of the tumor will be removed first, and then the basal part of the tumor will be removed and sent for pathological examination separately, and the basal part should reach the muscle layer of the bladder wall. When the tumor is large, it is recommended to cut the bladder mucosa around the tumor and send it for pathological examination because there is a possibility of in situ cancer in this area. In order to obtain accurate pathological results, it is recommended to avoid cauterizing the tissues during TUR to minimize the damage to the tissue structure of the specimen, or to use biopsy forceps to biopsy the base of the tumor and the surrounding mucosa, which can effectively protect the specimen tissue from damage.