Assessing the network vulnerability and finding out the weak links of network are the important basic work to keep the normal and reliable operation of power telecommunication network. On the basis of predecessors' research, a method of power telecommunication network vulnerability based on link used rate is proposed. Firstly, the vulnerability of topology structure is analyzed. Then the main parameters of network operation are ascribed to the link bandwidth. And the analysis of network vulnerability based on link used rate is made to find out the network weak spot. Finally, the topology structural vulnerability is combined with the operational vulnerability to calculate the vulnerability of power telecommunication network as a whole. And through the analysis of a network with 14 nodes, it can get the nodes fragility and the whole vulnerability of network. Then the research method of power telecommunication network vulnerability based on link used rate is verified. This work is supported by Science and Technology Support Project of Sichuan Province (No. 2017GZ0349).