Objective: On the basis of the dominant frequency index of functional connectivity, the "brain age" analysis method was used to explore abnormal development patterns of sensorimotor networks in boys with autism spectrum disorder(ASD). Methods: The resting state functional magnetic resonance data (7-12 years old) for 105 boys with ASD and 102 matched boys with normal development from the ABIDE public database were screened. Functional connection networks in different frequency bands of sensorimotor related brain regions were constructed for each individual, and the frequency of the strongest connection were constructed as the optimal frequency of the connection. Brain age analysis was used to explore the difference between brain age and chronological age in boys with ASD. Results: The brain sensorimotor network of boys with ASD showed an abnormal development pattern of overdevelopment followed by underdevelopment, and the transition between the two patterns occurred at approximately 7.8 years of age. Older boys with ASD (older than 10 years) whose underdevelopment trend was suppressed had lower ASD severity( r=-0.43, P < 0.05 ). Conclusion The brain sensorimotor network in boys with ASD has an abnormal development process, and the brain chronological age difference in the sensorimotor network has potential as a neuroimaging marker to measure the development of ASD.