In order to solve the problem that the cost of operation and erection of distributed cloud energy storage system in intelligent micro grid is high and it is difficult to find an effective overall control law, an observer-based controller design method is introduced. Based on segmentation affine Lyapunov function, use projection principle and several basic lemmas, and find out an approach of designing observer-based robust H? feedback controller. Acquire close loop control system feedback controller gain and observer gain. Compare the cloud energy storage power supply system with the traditional power system. The system result shows that the new energy utilization ratio is higher and the traditional energy grid system power consumption is lower by using the observer-based h-infinite control method to establish energy grid.