The security of power transmission network is directly related to the stable operation of the power system. In response to the complexity of indicator set of risk evaluation system and intensive time-consuming of a single risk evaluation process, a risk evaluation model added attribute reduction function is proposed. On the basis of the initial index system, the index system is reduced by using the rough set attribute reduction algorithm based on importance degree, and then the risk assessment results are calculated according to the network node risk calculation processes and models. The experimental results show that the improved model can effectively shorten the system evaluation time, and finally the risk point analysis and control system of power communication network is designed and implemented.