Abstract: The geographical dispersion of photovoltaic (PV) energy and its unstable power output can lead to load imbalance in distribution networks when integrated on a large scale. To address this issue, this paper proposes a hierarchical coordinated control strategy based on virtual synchronous generator and adaptive virtual DC generator (VSG-AVDG) for multi-terminal flexible interconnected distribution systems, aiming to solve the DC bus voltage stability problems caused by PV output fluctuations and operating mode switching. A deep integration mechanism for AC/DC virtual motor control is constructed. Specifically, the AC layer improves virtual synchronous control through DC outer-loop voltage compensation to achieve fast tracking of the DC bus voltage, while the DC layer proposes an adaptive virtual DC generator control strategy. Simulation results show that the proposed strategy can significantly suppress DC bus voltage fluctuations, reducing the fluctuation amplitude by approximately 50% and shortening the recovery time by about 33%, effectively improving the dynamic response performance and overall stability of multi-terminal flexible interconnected distribution systems.