PSA is called prostate-specific antigen (PSA) in Chinese, and it has a high specificity to assist in the diagnosis of prostate cancer by detecting the concentration of PSA in the patient’s blood, although bone metastasis is the most metastatic site in the advanced stage of prostate cancer. Although bone metastasis is the most common site of metastasis in the advanced stage of prostate cancer, there is no exact relationship between PSA and whether prostate cancer has bone metastasis, that is to say, no matter how much the PSA is, it cannot diagnose or suggest that prostate cancer has bone metastasis. In other words, no matter what the PSA is, it cannot diagnose or indicate the occurrence of bone metastasis of prostate cancer. In order to clarify the bone metastasis of prostate cancer, it is still necessary to carry out whole-body bone scanning or CT, MRI and other imaging examinations.