Embodiments of the present invention provide a route advertisement method, and controller, where the method is applied to a BGP-based routing network, a physical controller in the routing network is connected to multiple physical routers, and the method includes: receiving, by the physical controller, routing information reported by at least one physical router; obtaining a traffic path in which the at least one physical router is used as an egress router to transmit traffic to a destination router; generating a route for a physical router in the traffic path; and delivering the generated route to a corresponding physical router. In these embodiments, it is avoided that congestion occurs at an egress router, and a router that receives the traffic may generate a route for the router according to the traffic path so as to transmit the traffic to a next-hop router of the router without a need of recalculation.