Link importance is a key data in a power communication network. If the importance of some links in the network is too high, the failure of these links may bring irreparable losses to the network. On the contrary, if the importance distribution of links in the network is more uniform, the loss caused by the failure of a link is relatively small. This paper will carry out routing optimization for network services to achieve the goal of network risk reduction and reduce network risk. This paper constructs a power communication network model with active/standby routing service based on SDN architecture, and proposes a service routing optimization algorithm for power communication network under SDN architecture. According to the analysis of simulation results, it is concluded that the algorithm has significant effect on reducing network risks.