Abstract: Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder, which mainly include social communication disorder, restrictive interest and stereotyped behavior. However, there are large individual differences among ASD patients. Currently, its diagnostic results are subjective and random. Resting-state functional magnetic resonance imaging (rs-fMRI) can accurately quantify the changes of abnormal cerebral cortex function in children with ASD, which can provide reference for early clinical diagnosis and intervention of ASD, and may become an objective indicator for early clinical diagnosis and clinical intervention evaluation of children with ASD in the future. In view of the status quo of imaging research and the progress of research on the cerebral cortex function of children with ASD, this paper reviews the changes in brain function areas related to social communication, cognitive language and stereotyped behavior in preschool children with ASD, so as to provide references for early diagnosis of ASD and accurate evaluation of clinical intervention.