The exact location of Bladder Yu is in the sacral area, transverse to the second posterior sacral foramen, 1.5 inches adjacent to the median sacral crest, and can be used for treating conditions caused by bladder qi and chemical dysfunction and strong pain in the lumbar spine. Bladder Yu is between the beginning of sacroiliac muscle and the beginning of gluteus maximus muscle, under which there are posterior branches of lateral sacral vein and artery, and there is a genus branch of gluteus medius cutaneous nerve gluteus infundibular cutaneous nerve, so attention should be paid to the depth of needling. Bladder Yu belongs to the foot solar bladder meridian points, is the back of the bladder Yu points, can be used for the treatment of enuresis, urinary incontinence (urine not smooth), constipation, diarrhea, lumbar spine strong pain and other conditions. Acupuncture of Bladder Yu needs to be operated by acupuncturists after identification by a professional acupuncturist, and should not be operated by oneself to avoid adverse reactions.