A Multibit Trie is created for routing distribution of IP prefixes in each Virtual Private Network (VPN); and each Multibit Trie is divided into multiple layers. When routing search is performed for an IP address of a VPN, an input key is generated for each layer respectively, the input key of the layer comprises a VPN identifier of the VPN and bits corresponding to all of at least one layer before the layer in the IP address. A calculation is performed for the generated input key of each layer by using a Hash function of the layer, and routing is searched for according to a data structure information pointer of a Sub_Trie node corresponding to a longest Hash hit result.