Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with etiology encompassing the influences of genetic and environmental factors at both individual and population levels, among which maternal immune activation (MIA) is one of the high-risk environmental factors. Recent years have witnessed numerous related studies finding that the causes of autism in offspring induced by maternal immune activation may include dysregulation of inflammatory factors, metabolic alterations and oxidative stress, as well as gut microbiota disturbances, yet the specific mechanisms remain unclear. This article intends to review the theoretical hypotheses related to maternal immune activation-induced autism in offspring, providing insights into the research on the etiology, prevention, and treatment strategies of Autism Spectrum Disorder (ASD).