The early clinical manifestations of brain injury are often not easily appreciated and thus miss critical treatment time. Early identification of brain injury symptoms is mainly from the following aspects: 1, body tenderness and reduced spontaneous movement: this is a symptom of hypotonia, which can be seen at one month. If it lasts for more than four months, attention should be paid to the occurrence of severe brain injury, mental retardation or muscular system diseases; 2, body stiffness: this is a sign of hypertonia, which can be seen at one month, if it lasts for more than four months, attention should be paid to the occurrence of cerebral palsy; 3, unresponsive and unresponsive to name calling: this is a sign of mental retardation; 4, abnormal head circumference; 5, poor weight gain and difficulty in breastfeeding; 6 If the infant cannot smile at 2 months and cannot laugh at 4 months, the occurrence of mental retardation should be noted; 8. Head instability: If an infant at 4 months of age cannot raise his head in prone position or cannot hold his head upright in sitting position, it is often a sign of brain injury; 11. If the hand is still present after 6 months of age, mental retardation may occur.