Modern power systems heavily rely on the associated cyber network, so it is crucial to develop novel methods to evaluate the overall power system adequacy considering the substation cybersecurity issues. In this study, human dynamic is applied to simulate the temporal behavior pattern of cyber attackers. The Markov game and static game are utilized to model the intelligent attack/defense behaviors in different attack scenarios. A novel framework for power system adequacy assessment incorporating the cyber and physical failures is proposed. Simulations are conducted based on a representative reliability test system, and the influences of critical parameters on system adequacy are carefully examined. It is concluded that effective measures should be implemented to ensure the overall system adequacy, and informed decisions should be made to allocate the limited resources for enhancing the cybersecurity of cyber-physical power grids.