Aiming at time-varying feature identification of important brain regions in brain functional network based on fMRI-BOLD signal, a method of constructing time-varying observation model of dynamic brain network Rich-club is proposed in this paper. By clustering the similarity of Rich-club set of all time sampling points for one people, the temporal and spatial information of the brain function network is fused, and then the dynamic Rich-club importance evaluation model for brain network is built, which can describe the spatiotemporal comprehensive importance of the important brain regions quantitatively. Our work presents an effective method for the dynamic feature observation of the important brain regions in brain dynamic function network, and it also provides a basis technology for analyzing the differences of the important brain regions between healthy people and autistic people.