Microgrid is one of the most effective technique means for promoting the development of distribution power generation and renewable energy. In order to realize the modular design and friendly operation for the microgrid, this paper proposes a new modular topology for the AC-DC mixed microgrid which is encapsulated by the back-to-back converter. Also, the control algorithm for the multiple operation modes of that modular microgrid topology is studied. By the reasonable design on the topology and the location of battery-supercapacitor hybrid system in the microgrid, the hybrid energy storage system could supply the rapid power and energy support for the microgrid system under different operation modes. At the same time, the energy storage merits of battery and supercapacitor are fully developed. It can be indicated by the simulation analysis that the modular topology of microgrid and the control strategy are feasible, and therefore the seamless switching between the grid-connected mode and the isolated mode becomes the natural property for the modular microgrid. Furthermore, it can conclude by that simulation that the active and reactive power of the modular microgrid can be dispatched precisely. As a result, the microgrid can be considered as a power/load module with multiple characteristics to realize the friendly power interaction with the power grid.