The invention relates to a power supply zone interconnection point addressing method and system. The method comprises steps that the power supply zone is determined as the transmitting end power gridpower supply zone or the receiving end power grid power supply zone according to the supply capacity; sites within power supply zones are set as alternate nodes, the alternate nodes of the transmitting end power grid power supply zone are transmitting end alternate node, and the alternate nodes of the receiving end power grid power supply zone are receiving end alternate nodes; the transmitting end alternate nodes and the receiving end alternate nodes are screened according to preset screening conditions, and interconnection points of the transmitting end power grid and the receiving end powergrid are respectively determined. The method is advantaged in that an access scheme can be rapidly evaluated, computational complexity is small, electricity transmitting and receiving capabilities ofthe alternate nodes are considered, and the basis is provided for specific site selection of the flexible DC transmitting and receiving power grid.