Embodiments of the present invention provide an anchor gateway switching method, apparatus, and system, related to the field of communications technologies. This avoids transmitting a packet in a roundabout forwarding path. The method includes: determining, by a 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 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, so that the SDN switch forwards the downlink packet to the target anchor gateway based on the updated forwarding flow table, and the target anchor gateway forwards the downlink packet for the terminal. The method is applied to an anchor gateway switching scenario.