With the rapid development of new energy industry and technology, people's research and application of new energy such as photovoltaic are gradually increasing. The combination of new energy generation such as photovoltaic and traditional power grid will produce the impact that electric energy cannot be used efficiently, based on this, some scholars have proposed flexible Internet technology to realize flexible interconnected power distribution. As the core device in the flexible interconnection distribution, the power router undertakes the transformation and distribution of electric energy, and realizes the interconnection of multiple information and interoperability of multiple energy sources in the flexible interconnection distribution. The stability of the PV energy storage router in the flexible interconnection is the key to the flexible interconnection power distribution, which has important research significance and is the main subject of this paper. The paper mainly improves the traditional four-port energy router topology with PV DC port and energy storage port, and adopts the interleaved parallel BOOST circuit topology, and establishes the impedance model of PV energy storage direct energy router based on flexible interconnection under this improvement, and gives the stability analysis method based on the impedance model.