Abstract: The features of microgrid technology in operation mode,capacity and voltage level,structure mode,connection mode are overall analyzed and summarized.Furthermore,the researching method and thinking of various key technologies about optimization design,operation control,security,economic operation of microgrid are introduced.This paper summarizes the typical characteristics and key technologies of actual microgrids around the world,and makes a prospect of various new technologies and research orientation of microgrid,as well as meaningful suggestions for the future research and development of microgrids in China.