Abstract: Aiming at the current difficult subjects of complex power cyber physical systems(CPS) system, network coupling and vulnerability analysis, a damage tree model of power CPS was established based on the research results of power system damage assessment in recent years. Considering the node importance and fault cascade damage characteristics of power CPS network, a vulnerability analysis method was proposed based on node importance for power CPS, and analyzed and illustrated with examples. Results show that the model can be used to study the survivability of power cyber physics system and can provide a support for the design and improvement of target damage resistant structure.