A method for network handover includes sending a first message that includes first information to a second network, where the first information is used to indicate that a user equipment needs to be handed over from a first network to the second network, so that a target gateway device allocates, to the user equipment according to at least the first information sent by the second network, a second Internet Protocol (IP) address that is the same as a first IP address and used when a second packet data network (PDN) connection is established by using the second network and the target gateway device, where the first IP address is an IP address used when the user equipment establishes a first PDN connection by using the first network and the target gateway device. Therefore, service continuity is ensured after a network handover.