Due to the high geographic overlap and functional dependence of information equipment and power equipment

fault propagation across the network due to dependence and information transmission failure has become a new characteristic of cascading failures in cyber-physical power system (CPPS). In order to identify the key coupling nodes of CPPS and guide the safety prevention and control of power grid

this paper constructs an improved PageRank (PR) algorithm for the fault propagation characteristics of power grid

and uses the voltage safety margin index as the damping factor to dynamically coordinate the active power transmission and voltage sensitivity. For the inter-network fault propagation characteristics

the functional coupling relationship of nodes is established and mapped to the load state and network efficiency index of the information network

and the CPPS coupling key node identification method is proposed. This paper proposes a validation method based on CPPS cascading failure simulation to evaluate the effect of successive attacking nodes with the coupled network connectivity and source-load adjustment cost as the indexes

which verifies the validity and superiority of the proposed CPPS coupling key node identification method.