Abstract: With the increase of social demand and continuous development of the power grid technology, the flexible interconnected distribution network has gradually become the development trend of smart grid in the future. However, access of large-scale distributed generation with high permeability into the power grid and complicated control strategy of the power electronic devices have brought severe challenges to the development of flexible interconnected distribution network. Therefore, this paper firstly analyzes advantages of the flexible interconnection distribution network compared to the conventional distribution network, and introduces the corresponding development opportunities and challenges. Then it reviews the key equipment and technologies, the structure morphology and the key technology for operation control of the flexible interconnection. Meanwhile, it analyzes the basic structure and principle of flexible interconnection devices such as the soft open point (SOP), the flexible loop network controller (FLNC) and the power electronic transformer (PET). Finally, it explores the key development problems of the flexible interconnected distribution network under the new situation based on current research so as to provide scientific basis and reference for the development of flexible interconnected distribution network.