Based on an event-triggered mechanism，load frequency control of multi-area interconnected power systems under aperiodic denial-of-service （DoS） attacks is studied.First，a mathematical model of the multi-area interconnected power system under aperiodic DoS attacks is established.Then，a switching state observer is designed to estimate the states during the hibernating and active periods of the aperiodic DoS attacks，respectively.To save communication resources，an event-triggered mechanism is introduced into the observer-controller channel.Moreover，based on the state observer，a feedback controller is designed.Finally，the three-area interconnected power system is taken as an example to make a simulation-based verification.The simulation results demonstrate that the proposed control method can restrain the adverse impact of the aperiodic DoS attacks effectively.