Unseen lymph node metastasis of prostate cancer means that prostate cancer has occurred and regional lymph node metastasis has not yet occurred. Prostate cancer occurs in older men and is a common malignant tumor in older men, and the common pathological type is follicular adenocarcinoma. Usually, patients who are suspected of having prostate cancer can undergo prostate aspiration biopsy to confirm the diagnosis. No lymph node metastasis means that the cancerous tissue has not invaded the regional lymph nodes. The treatment of this type of cancer needs to take into account the depth of infiltration and whether it has metastasized to formulate the treatment plan. The key to the treatment of prostate cancer is early detection and early treatment. Patients suspected of having prostate cancer can be screened by means of rectal palpation of the prostate, serum PSA test, imaging and so on, and after diagnosis, the depth of infiltration, whether there is lymph node metastasis or distant metastasis can be evaluated by means of MRI, CT and other means to carry out clinical staging, and choose the treatment plan in combination with the systemic condition of the patient.