Hydrocephalus is a general term for an increase in cranial pressure and enlargement of the ventricles secondary to an excess of cerebral crest fluid and an increase in pressure due to a disorder in the production or circulation and absorption of cerebral crest fluid. The clinical symptoms are not consistent and are related to the age at which the pathological changes appear, the severity of the pathology, and the length of the disease. Fetal congenital hydrocephalus mostly results in stillbirth, and hydrocephalus may appear at any age after birth, mostly in the first 6 months of life, and in younger patients the cranial suture is not joined and the head is easily enlarged, so the symptoms of increased intracranial pressure are fewer. The normal infant’s head circumference increases by 1.2-1.3cm per month in the earliest six months, but it is 2-3 times larger in this disease, the skull is round, the frontal part protrudes, the fornix of the head is abnormally enlarged, the fontanelle expands and bulges, the cranial suture separates, the skull becomes thin and even transparent, the percussion can appear “broken pot sound” (Maceen) sign, the temporal frontal part presents angry veins, the eye The infant is depressed and cannot lift the head. In severe cases, the infant may have brain dysfunction, including epilepsy, visual and olfactory impairment, nystagmus, strabismus, limb paralysis and mental retardation, etc. Because the infant’s head is compensated for the enlargement, headache, vomiting and optic nerve papilla edema are not obvious. After the formation of hydrocephalus, the cerebral crest fluid circulation pathway is blocked and causes secondary changes in brain tissue: the ventricular system expands due to the accumulation of cerebral crest fluid, and as the ventricular wall is stretched, the ventricular canal membrane gradually disappears and the ventricles are surrounded by astrocytosis or glial scar formation. Further enlargement of the ventricle may cause white matter edema due to the entry of cerebral crest fluid into the periventricular tissue. At this time, even if a cerebral crest fluid shunt is performed to restore the ventricle to its normal size, the histological changes in the brain tissue cannot be restored.