The functions of information system should be realized through the information network. Different damaged degrees of information network correspond to different functional states of the information system

which affects the emergency response capacity of the power system. Research on the impact of information network damage on cascading failures of power grid is an important topic for ensuring safe operation of the modern power network. A model of cascading failures in a power grid considering the impact of information network damage is built. Damage indices of the structure of information network and functions of information system are proposed to analyze the impact of different damaged degrees of information network on cascading failures. From the perspective of regional distribution and individual importance of failure edges

the impact of information network damage on cascading failures is investigated with several failure modes. Results of an IEEE 30-bus system show that the ability to restrain the propagation of cascading failures is weakened by the damaged information network

which leads to the spread of cascading failures. When the power grid is under a heavy load level

the impact of information network damage on cascading failures is more apparent. Differences in the scale of cascading failures are obvious among different failure modes

and structural vulnerability of information network is an important factor affecting the spread of cascading failures of power grids.