User network attaching method and system for roaming scene in 3GPP evolution network

This invention relates to a user network adhering method and a system at panning scene in a 3GPP evolution network, in which, the method includes: A, a terminal sends an adhesion request to an access evolution core network, which distributes a first IP address for the terminal, B, the core network analyzes information of a terminal attribute evolved core network to register to the terminal attribute evolved core network, C, the attribute core network distributes a second address for the terminal and binds the two addresses, D, the access network gets to know the binding relation of the two addresses and feeds back the related information to the terminal. This invention also discloses a user network adhesion system in 3GPP evolution network at panning scene.