Embodiments of the present invention provide a traffic offload method, a core network device, and a traffic offload system. The method includes: sending, user information that is of a user equipment within coverage of a first traffic offload function entity to the first traffic offload function entity; sending a traffic offload policy to the first traffic offload function entity, so that the first traffic offload function entity matches the user information with the traffic offload policy and offloads traffic corresponding to the user equipment according to the user information that successfully matches the traffic offload policy.