Flexible and interactive smart grid encourages users and grid have a positive interaction. The user and the grid can get mutual benefit and win-win results in smart grid. The real-time electricity price can be a way of the grid releasing requirements. At the same time, PV system, energy storage system and electric vehicle provide possibility for the house positive response to the grid. Based on the real-time electricity price environment, in a micro grid including PV system, energy storage system and electric vehicle, this paper takes the storage system and the electric vehicle as the main loads of the house participate in the energy optimization. First, it establishes the battery charge/discharge model and the electric vehicle charging model. Second, it establishes the micro grid system energy optimization model with minimum the total cost as the goal. Then the mixed integer linear programming method is used to solve the model. Finally the simulations verify that the model can effectively reduce the system operation cost. This work is supported by the Education Committee of Beijing Basic Research Program of China (No. XN097) and Foundation of Collaborative Innovation Center of Key Power Energy-Saving Technologies in Beijing (No. PXM2016_014212_000016).