The present invention provides a method and an apparatus for topology aggregation and a routing controller. The method comprises: obtaining a link-diversity path number c(i,j,λk) between each pair of border nodes in a real topology GR; and obtaining a connectivity matrix C by utilizing said link-diversity path number c(i,j,λk) and constructing a corresponding full-mesh topology GB. Moreover, the method further comprises compressing the resulting full-mesh topology into a bi-directional shuffle-net topology using the genetic algorithm. Therefore, according the present invention, more link information can be provided for routing decision and more accurate topology can be provided.