The fault distribution network with a high proportion of distributed power supply access possesses active recovery and self-governance capabilities, which is conducive to enhancing the power system's adaptability to climate change and disaster risk management, aligning with the development direction of distribution network technology. Currently, research on active islanding self-recovery and stable operation of distribution networks has received widespread attention. This paper begins with an overview of the connotations of active islanding in multi-source distribution networks, as well as the distinctions between multi-source distribution network islands and microgrid islands. It then analyzes and summarizes the key issues that arise in the stable operation of active islands in distribution networks with a high proportion of distributed power supply integration. Subsequently, the paper elaborates on the current research status from three aspects: active islanding partitioning, fluctuation mitigation control for island self-networking, and small signal stability control for active islands after networking completion, followed by a summary. Finally, based on the internet of things for power, small signal suppression in the context of high power electronics, and active islanding solutions within the framework of the energy internet, the paper provides an outlook and summary on the development prospects of active islanding in multi-source distribution networks.