The network layer includes at least two levels of management domain. The method includes following step: (a) measuring switching intensity of current management domain and adjacent management domain; (b) based on measured result of switching intensity, adjusting management ranges of current management domain and adjacent management domain forms structure of management domain in new levels with minimum switching spending. The invention measures switching intensity in real time, evaluates network spending, and based on evaluating result, subordination of management domain in network is changed dynamically. Thus, network hierarchy can be self-organized based on practical situation so as to reduce signaling spending in network, as well as raise service quality of network.