Cognitive function involves the adaptive behavior of brain organization, which is the advanced behavior of problem solving, remembering information, and focusing attention. Children’s cognitive function involves learning ability, attention, memory, intelligence, and other aspects, and the four are closely related. They influence each other. Academic performance is one of the important manifestations of learning ability. Recent studies have shown that the cognitive impairment of some children with epilepsy is mainly manifested by decreased intelligence, memory impairment, inattention and learning difficulties. Many children with epilepsy are unable to complete primary or secondary school, which seriously affects their educational level and causes difficulties in career seeking, marriage, family and social interaction in adulthood, and their quality of life is significantly reduced. The main factors affecting the cognitive function of the child include: seizures, subclinical epileptiform discharges, seizure type, and antiepileptic medication application. Studies have concluded that the younger the age of onset, the longer the duration of the disease, and the higher the frequency of seizures, the greater the impairment in cognitive function. Subclinical discharges, i.e., epileptiform discharges shown on the interictal EEG, can also cause impairment of cognitive function in children, and persistent discharges during sleep often cause intellectual impairment, with the longer the duration, the more severe the intellectual impairment. Epileptic discharges under clinical conditions damage neural tissue, especially developing brain tissue, reducing the ability of neurons to respond to information, interfering with neural uptake, processing and storage of information, and impairing memory consolidation. Grand mal seizures and complex partial seizures have a significant impairment of cognitive function in children. Some antiepileptic drugs also have significant cognitive impairment, such as phenobarbital and phenytoin sodium. The correct diagnosis and classification of epilepsy, as well as the correct combination of treatments, can minimize the cognitive impairment of children with epilepsy.