Normal cranial pressure hydrocephalus is also called normal pressure hydrocephalus. If a patient has significantly enlarged ventricles, unstable lower limb walking, urinary incontinence and mental retardation, surgery needs to be considered. For normal pressure hydrocephalus, the recommended surgical option is ventriculoperitoneal shunt surgery. The principle of the surgery is to drain the excessive cerebrospinal fluid from the ventricles into the abdominal cavity to achieve the purpose of treatment. The other end of the drainage tube is implanted subcutaneously into the abdominal cavity.