1. A method for realizing a Virtual Network (VN), comprising: setting a virtual network access point (VN-AP) in a data center network and/or a broadband network; receiving, by a service deployment and management function entity, a VN service request from a user to generate feature information of the VN; and automatically discovering the VN-AP by a Personal Computer (PC)/Virtual Machine (VM); generating, by the automatically discovered VN-AP, a VN forwarding table entry of the PC/VM after the PC/VM passes VN's identity authorization, and performing tunnel encapsulation according to the VN forwarding table entry to forward a packet from the PC/VM.