Abstract: In addressing the security assessment of power dispatch networks based on practical quantum key distribution（QKD）， the vulnerability assessment theory of communication networks was employed to construct a comprehensive security assessment method integrating power dispatch services， network structures， and network attacks. Besides， the impact of quantum key distribution on overall security was also studied. The results indicated that， when conducting an overall security assessment of power dispatch networks， in addition to the vulnerability of the communication network itself， the weights of corresponding dispatch sub-services and network attacks also significantly influenced the security score. The integration of quantum key distribution might introduce new quantum eavesdropping attacks， and reducing the corresponding bit error rate would effectively enhance system security.