In order to make the centralized differential protection methods being better applied, it is necessary to control the distribution network partition to adapt the request of data acquisition and processing, since the number of buses and branches are large in the distribution network. This paper transforms the distribution network into a weighted network of generalized nodes, and then abstracts it in the view of graph theory. The network is partitioned according to the topological structure of each node. A new theory called Absorbing Method is put forward to simplify the abstract model of distribution network and deal with it by looped network continuously, through which a complex network is partitioned into some generalized node regions.