Embodiments of the present disclosure provide an anchor gateway switching method, apparatus, and system. The method includes: determining, by a control plane (CP) device, to switch a source anchor gateway; obtaining, by the CP device, location information of a terminal; determining, by the CP device, a target anchor gateway based on the location information; and sending, by the CP device, a modification request message to an software defined network (SDN) controller, where the modification request message includes an identifier of the terminal and an identifier of the target anchor gateway, the modification request message is used to notify the SDN controller to: update, based on the identifier of the terminal and the identifier of the target anchor gateway, a forwarding flow table corresponding to a downlink packet, and send an updated forwarding flow table to an SDN switch.