There is no such thing as mild encephalitis in pediatrics, which generally refers to encephalitis with relatively mild clinical manifestations, which has a variety of clinical symptoms with different manifestations. In mild cases, there may be symptoms such as poor mental health, irritability, fever, headache, etc., and in severe cases, there may be symptoms such as coma, convulsions, projectile vomiting, hemiparesis and aphasia. Pediatric encephalitis is mostly caused by viral and bacterial infection of brain tissue, the performance varies in severity. When the intracranial pressure is too high and the damage to the brain tissue is not too serious, the children only show changes in mood, poor spirit, lethargy, poor appetite, or irritability, vomiting, headache, and most of them have a low fever, or even no fever, and most of them do not have any manifestation of damage to the brain parenchyma. When the pediatric intracranial pressure increases significantly, or the brain tissue damage is more serious, there will be frequent projectile vomiting, or even coma, persistent convulsions, which may be accompanied by hemiparesis of the limbs, unsteady walking, or even aphasia. When the baby is suspected of having symptoms of encephalitis, it is recommended to consult a pediatrician in a timely manner to clarify the cause of the disease and take targeted treatment to avoid delaying the condition.