Determining whether a child has encephalitis is mainly based on the child’s clinical manifestations and auxiliary examinations. First of all, if it is herpes simplex virus encephalitis, at the onset of the disease, patients will have obvious changes of headache, nausea, vomiting, and there will also be slight changes in consciousness and personality, and some patients will have hemiplegia, hemianopsia, hyperactivity and other symptoms. At the onset of viral encephalitis, patients tend to have attacks in the summer and fall. Systemic symptoms of viral infection, such as dizziness, headache, generalized, muscular pain, and loss of appetite, may occur at the onset of the disease. Tuberculosis encephalitis may be characterized by symptoms of tuberculosis toxicity, such as low-grade fever, night sweats (sweating abnormally after going to sleep and stopping after waking up), mental instability, and may be accompanied by fever, headache, nausea, vomiting, and other symptoms. When the new cryptococcal encephalitis develops, the patient’s onset is more insidious, and there will be fever, headache and other symptoms, and with the progress of the disease there will be irritability, memory loss, and in severe cases, the patient will have a consciousness disorder. Secondly, in addition to the clinical symptoms of meningitis in children, it should be combined with cerebrospinal fluid examination, CT or MRI to make a clear diagnosis.