Low free-to-total PSA ratio may be caused by benign prostate diseases or prostate cancer, which needs to be analyzed according to the ratio data, total PSA index, and other examination results, and can be treated by surgery, radiotherapy, and medication after clarifying the cause.1. Benign prostate diseases: benign diseases such as prostatitis and prostate hyperplasia may have low free-to-total PSA ratio, but the total PSA level remains in the normal range, and the patient may have symptoms such as urinary pain, urinary pain, and urinary pain. PSA levels remain in the normal range, and patients may experience symptoms such as urinary pain and urgency, which can be clearly diagnosed and treated through ultrasound and urine culture. Prostatitis can be treated with antibacterial drugs such as erythromycin and levofloxacin, and prostate hyperplasia can be treated with drugs such as doxazosin and finasteride, and surgical treatments such as transurethral resection of the prostate and laser resection of the transurethral resection of the prostate can be performed if necessary. 2. Prostate Cancer: If only the ratio of free to total PSA is low, it may also be caused by prostate cancer, and symptoms such as frequent urination, urgency, and increased nocturia can be seen. However, it is also necessary to do prostate enhancement magnetic resonance and prostate puncture biopsy to make a clear diagnosis. After diagnosis of prostate cancer, radical surgery, such as laparoscopic resection, should be carried out in time. Patients who cannot undergo surgery can be treated with radiotherapy, chemotherapy, targeted therapy, and endocrine therapy.