Abstract: Using power electronic devices represented by soft open points, energy routers, and smart power/information exchange stations to realize the flexible interconnection of the distribution network, and better adapting to the integration of multi-sourcestorage-load devices, will be the development trends of the future smart distribution network. Starting from the concept of flexible interconnected smart distribution networks, the paper introduces in detail the topological structure and working principle of its core devices, i. e. flexible interconnected devices. Meanwhile, the research status and difficulties of key technologies of flexible interconnection smart distribution networks such as planning and design, operation control and fault self-healing are analyzed.Finally, the technical fields that need to be studied in the future and the engineering application prospects are discussed and prospected.