In this paper, we propose an evaluation method to assess the optical network in the power grid. A set of evaluation indices is selected to characterize the different aspects of the network. Not only the network reliability but also the service support ability and the network developability are taken into consideration, which leads to a comprehensive evaluation result. The assessment is based on a hierarchical model and an evaluation algorithm. An example is presented to show the detailed operation of the evaluation process and verify the effectiveness of the given approach.