This paper studies the smart control issue for large power systems to effectively solve the problems of security, stability, and economical efficiency. A control scheme called as hierarchical hybrid control is proposed versus the hierarchical structure and hybrid dynamics of large power systems. A novel hybrid model is first founded to clearly explain the interactive hybrid behaviors of the power systems during significant disturbances. On the basis of the model, the hybrid control is proposed, which consists of upper level control strategies (including logic control commands for discrete events and energy management strategies) and lower level continuous controls for component units. The upper level control strategies are responsible for switching operating modes for the purpose of security operation following a significant disturbance, as well as power assignment for the economical efficiency of operation, and the lower level continuous controllers are responsible for regulating dynamic stability of the systems. The effectiveness of the proposed hybrid control is demonstrated through simulation examples.