The invention relates to a virtual network mapping method and system based on a multi-fiber-core optical network, and the method comprises the steps: evaluating the overall mapping degree of a physical node in a node mapping process of a space division multiplexing elastic optical network based on the available resource capacity of an optical repeater in the physical node and the available resource capacity of an adjacent link of the physical node; selecting an optimal physical node matched with each virtual node according to the overall mapping degree of the physical nodes, and mapping the virtual nodes to a physical network in sequence; in a link mapping process of a space division multiplexing elastic optical network, using a distance self-adaption method for selecting a corresponding transmission mode according to the length of a link transmission distance, using a First Fit algorithm for selecting a scheme which occupies the minimum coordinate value of a spectrum position and is most matched in a pre-defined link resource allocation scheme, and mappig the link to a physical network in sequence.