Method for selecting shared protection path

The invention relates to the technical field of quantum communication, in particular to a method for selecting a shared protection path. The method comprises the steps of obtaining a plurality of alternative protection paths corresponding to a preset forwarding device and the number of services protected by each alternative protection path; determining the wavelength resource cost of the alternative protection path based on the number of services protected by the alternative protection path; wherein the resource cost is negatively related to the number of services; obtaining the exhaustion time of the secret key in the secret key pool corresponding to each alternative protection path; determining a weight index of preset forwarding equipment under each alternative protection path accordingto the key depletion time and the wavelength resource cost; and based on the weight index corresponding to each alternative protection path, determining one protection path from all the alternative protection paths. The math