The embodiment of the present invention provides a method for establishing a route, which includes searching a target node by a node from a first level node group according to first level route information, returning to query a result or data saved by the target node if the target node is found, otherwise executing the following step; searching a target node by the node from a higher level node group according to higher level route information, returning to query a result or the data saved by the target node if the target node is found, otherwise repeating the step. Through the hierarchical communication system, most of the flows of daily service operations in the communication network are limited within a small region, thereby preventing from excessively occupying the band width of a backbone network being originally not wide enough.