Abstract: The cyber physical fusion provides the support for the increasingly real-time demand of demand side load resource regulation. Aiming at the real-time control needs of the water heater group for the new energy consumption, a control strategy of water heater group situation awareness based on hybrid logic dynamic model and control strategy was proposed. Firstly, the situation awareness architecture was introduced to support the analysis and prediction of the system and mixed logic dynamic（MLD） model of water heater load group was built based on a hybrid system theory. The model integrated the continuous temperature of water heater, discrete switching and user behavior information in a common physical frame and lowers the computational complexity by introducing multi logical variables. Moreover an optimal control strategy based on variable value weights was proposed to improve the flexibility and effectiveness of water heater control. Finally, the simulation results show the good applicability of the proposed model and control strategy.