The close combination of power system and communication system in smart grid makes the power communication network more important in the system of interdependent network. The failure of nodes in the communication network, especially the important nodes, will not only affect their own network but also affect its dependent network, leading to the occurrence of chain failure. Therefore, it is of great significance to evaluate the importance of power communication network nodes in smart grid. In this paper, the single side network is extracted from the power physics-information network, and the subnet models are established with the link-used rate and power line impedance value as the edge weight parameter. According to the importance evaluation method of the weighted network node, the two subnets are analyzed separately. Then, on the basis of the dependent edge matrix of electric power subnet depending on the information communication subnet, it calculates the important index of power communication network nodes in dependent network and finds the important nodes. The IEEE30 node system is used as an example to demonstrate the feasibility and practicability of the method. This work is supported by Science and Technology Support Project of Sichuan Province (No. 2017GZ0349) and Science and Technology Project of State Grid Xinjiang Electric Power Company (No. SGXJXT00TJS1600206).