This application provides a path determining method and a related device. The method includes: determining N1 first-type nodes from N nodes included in a first network topology, where the N nodes include the N1 first-type nodes and N2 second-type nodes, and the first-type node supports SRv6; determining a second network topology corresponding to the first network topology, where the second network topology includes the N1 first-type nodes but does not include the N2 second-type nodes, and the target topology structure includes M first-type target paths; determining transmission overheads of the M first-type target paths, where a transmission overhead of an ith first-type target path is a smallest value of transmission overheads of a Ki paths; and performing path computation based on the transmission overheads of the M first-type target paths and the second network topology.