A topology structure discovery method and device. The topology structure discovery method comprises: a controller acquiring topology structures among N routers; according to the topology structures, the controller obtaining routing tables respectively corresponding to each router, and respectively sending corresponding routing tables to each router, wherein the routing tables comprise at least one kind of routing information between the router and other N-1 routers and routing information between the router and the controller, so that the controller can obtain the topology structures of the whole network and calculate the router capable of obtaining the optimal path according to the topology structures of the whole network, thereby improving the utilization efficiency and the throughput of the network.