The incidence of prostate cancer ranks second in malignant tumors in men in Europe and the United States, and is the third cause of cancer death in men over 55 years of age. Although the incidence rate of PC in China is lower than that of European and American countries, it has been increasing in recent years with the aging of China’s population and the change of diet structure. According to statistics, the incidence of PC in China has now increased by more than 50% compared to the 1960s, and there is a trend of rapid increase. The natural history of PC is unique, variable and unpredictable. Tumors can progress rapidly and lead to patient death, or they can remain latent for a long time and remain incapacitated for life. Early stage cancer can be effectively treated by surgery and application of androgen inhibitors, and the survival rate is close to 100% within 5 years; however, as the cancer level progresses, the tumor metastasizes to lymphatic metastases and distant organs such as bone, which is difficult to cure with current medical treatment, and the survival rate is only 31% within 5 years. Therefore, it is very important to explore the early diagnosis of PC. The first is that the prostate is often asymptomatic, but a hard node in the prostate is found on rectal examination or an abnormal echogenic area is found on ultrasonography, and the prostate-specific antigen is elevated. Therefore, for those who have risk factors for PC, regular physical examination and PSA examination should be performed. The presence of lower urinary tract symptoms (LUTS) such as urinary frequency, urgency, difficulty in urination, hematuria and hematospermia, as well as unexplained osteoporosis and musculoskeletal pain. 2. Rectal examination Rectal examination together with transrectal ultrasound and PSA measurement are the main methods of screening PC in clinical practice. Skilled DRE is one of the easiest, economical, practical and effective screening methods to detect PC, but early cancerous nodules are not easily distinguished from hyperplastic nodules, granulomatous prostatitis, tuberculosis, stones and other lesions. The positive result rate is closely related to the experience of the DRE examiner, and confirmation of the diagnosis needs to be combined with other tests. 3. prostate tumor markers PSA determination PSA is a glycoproteinase produced by the prostate epithelium. three types of PSA can be quantitatively detected in the blood at present: total PSA, free PSA, and bound PSA. 20% of PSA in the blood under normal conditions has a high probability of being benign; fPSA/tPSA 0.75 μg/L year, then its specificity for, PC diagnosis can reach 90%. If the PSA value increases by more than 20% per year or is greater than 0.75μg/L?year, DRE, TRUS or biopsy should be performed for early detection of PC. PSA density PSAD is the ratio of serum PSA value to prostate volume (ml) measured by transrectal ultrasound. there is a significant difference between PSAD of PC and BPH, if PSAD is increased, the possibility of cancer increases when DRE and ultrasonography are normal and serum PSA is 4-10 μg/L, prostate biopsy should be done if PSAD ≥ 0.15. A study was conducted on 61 patients, 41 of whom were PC with radical surgery and 20 with BPH, resulting in a mean PSAD of 0.581 in the PC group and 0.044 in the BPH group (P0.1; if 0.1 is the upper limit of PSAD, the sensitivity and specificity of the diagnosis of PC is 80.5% and 64.5%, respectively. The PSA metastatic zone density BPH is caused by hyperplasia of the prostatic metastatic zone, PC is often located in the peripheral zone, so there is no significant increase in the volume of the prostatic metastatic zone, PSAT is better than PSAD in distinguishing PG from BPH. PSAT = PSA/TZ. PSAT is important in clinical work for the early diagnosis of PC, differential diagnosis and for the selection of surgical options for tumors, especially for patients with mildly elevated blood The PSAT is important in clinical work for the early diagnosis of PC, differential diagnosis and for the selection of surgical options for tumors, especially for patients with mild to moderate elevation of PSA and those with large prostate volume. There is no definite standard for the selection of the threshold value of PSAT, and some suggest 2.0 as the threshold value. In addition, more researched indicators for detecting prostate cancer are: prostate-specific membrane antigen (PSMA), human adenokinin release enzyme 2 (hk2), insulin-like growth factor 1 (IGF, 1), ProPSA, etc., all of which can be used to assist in the early diagnosis of PC. The probability of PC occurring in the central zone, migratory zone and peripheral zone is 10%, 20% and 70% respectively. TRUS can detect lesions as small as 5, mm in diameter and has a good rate of showing benign and malignant nodules of the prostate. However, about 30% of PC has an atypical ultrasound presentation, as isoechoic and hyperechoic nodules, or is located in the endogland, making it difficult to detect on ultrasound or mistaken for hyperplastic nodules; and there are also hypoechoic nodules in BPH, which are not easily distinguishable from PC, so there is some overlap between the ultrasound features of PC and PBH. MRI, T2WI, the prostate itself is generally high signal, while the cancerous tissue is generally a relatively low signal nodule, so MRI has some advantages over CT in detecting PC. The PC tissue has metabolic disorders: choline (Cho) is significantly higher in tumor tissues, while Cho concentration is lower in tumor necrosis and cystic areas, and can be normal or higher in benign tumors. The concentration of citrate (Cit) in cancer tissues was significantly reduced or absent. Combining the characteristics of elevated Cho peak and reduced cit peak in PC tissues, the diagnostic rate and characteristics of PC can be improved. The combination of MRI and 3D2MRS is the most ideal method for detecting PC. The combination of MRI and 3D2MRS is the most ideal method to detect PC. (1) The main diagnostic criteria for MRI and MRS of PC are: (2) low signal nodules on a high signal background of the prostate on T2WI; (3) low signal nodules that break through the prostate envelope and invade the seminal vesicle gland or periprostatic tissue; (4) high Cho peaks on MRS; (5) a significant decrease in prostate-specific Cit peaks. (6), BPH generally has a homogeneous enlargement of the central zone and the migratory zone of the prostate, with a similar or slightly higher signal than the normal gland on T1WI and T2WI, and a smaller signal in the periprostatic zone due to atrophy and compression, with a more homogeneous signal in the hyperplastic gland. The prostate sarcoma is rare, more frequent in young people, with a rapid progression and short duration of disease. The first limitation of MRS is that the signal of MRS is easily contaminated by the surrounding powerful water and fatty signals, resulting in some tall and deformed waveforms that are difficult to interpret; the sensitivity and specificity of MRS is reduced by the partial volume effect of respiratory motion. It also greatly affects the quality of MRS generation. In addition, the spatial resolution of the magnetic field uniformity is also low, and the temporal resolution is also low, etc. 6, prostate puncture biopsy Prostate puncture biopsy is the only way to confirm the diagnosis of PC preoperatively, either transrectally or via perineal biopsy, the current conventional method is to perform prostate puncture biopsy using an automated biopsy gun system under transrectal ultrasound guidance, with increased puncture points, which can improve the diagnostic rate of PC. In addition, it is recommended to increase from the previous standard 6-point puncture to 8- or 10-point or even 13-point puncture to improve the diagnostic rate of PC. In conclusion, the key to improve the survival rate of PC patients lies in early diagnosis and timely treatment. At present, there are many methods for early diagnosis of PC at home and abroad, and new methods with higher sensitivity and specificity are emerging. Clinical attention should be paid to the danger signs of PC and to the examination of risk groups. Currently, DRE, TRUS and PSA are the main methods to screen for PC; MRS is important for the identification of prostate nodules; confirming the diagnosis relies on prostate puncture biopsy, and the positive rate of multi-point puncture has increased significantly.