Purpose: To explore the application of quantitative magnetic resonance imaging in the diagnosis of autism in children. Methods: All the children were scanned using head MRI conventional sequences, 3D-T1,DKI, ESWAN and 3D-pcASL sequences. The QSM, CBF and brain microstructure of each brain area were compared between the groups, and correlations were analyzed. Results: The frontal lobe, temporal lobe and hippocampal regions may be the first areas to show microstructural changes in autistic children . Conclusion: Quantitative magnetic resonance imaging can shows the abnormal changes of brain microstructural in children with autism .