In order to ensure the reliability of the remote dispatching network and improve the utilization efficiency of optical cable network resource, this paper presents a resource allocation approach based on fault link group separation to solve the problem of high resource cost and block probability of shared Backup Path Protection approach. In the construction of protection channel, management of protected resources can be allocated according to the formation of the resource link group. It utilizes the main routing and alternate routing tag to improve the utilization efficiency of backup channel, realizing the saving of the main working route resource. Finally, the proposed method is verified under different network simulation scenario, and the performance is also analyzed in theory.