In recent years, the incidence of prostate cancer in China has been steadily increasing year by year, ranking the first in male genitourinary tumors, with poor prognosis, and sounding the “alarm” for men’s health. So, how to achieve the early diagnosis of prostate cancer? Prostate-specific antigen (PSA) is by far the most specific marker of prostate cancer. Under normal circumstances, the contents of the PSA-rich prostate alveoli are separated from the lymphatic system by a barrier consisting of the endothelial layer, the basal cell layer and the basement membrane. In the case of prostate cancer, this barrier is broken and the glandular contents can leak into the lymphatic system and subsequently enter the blood circulation, resulting in an increase in peripheral blood PSA levels. Men over 50 years of age with lower urinary tract symptoms should be routinely screened for blood PSA and rectal finger examination. The promotion of serum PSA screening has led to an increasing rate of early diagnosis of prostate cancer and a significant improvement in patient survival and quality of life. Therefore, rectal finger examination combined with blood PSA test is now recognized as the best primary screening method for early detection of prostate cancer.