Quantum key distribution, as a physical principle-based encryption scheme, can circumvent the encryption risks associated with increased arithmetic power. With the gradual completion of hardware architecture, key relaying and distribution between nodes over long distances can be achieved, thus it becomes possible to implement quantum key encryption in large scale complex networks. In this paper, an adaptive link overhead routing algorithm for enhanced networks based on quantum key distribution is proposed, combined with a shortest path-based routing scheme that jointly determines link overheads according to link capacity and key generation rate, and simulation under 7-node and 10-node network topologies are completed.