The invention discloses a resource mapping method and device based on an SDN multi-domain optical network virtualization technology. The method comprises: when a virtual request is received, mapping the virtual nodes in the virtual request to physical nodes; aiming at every virtual link, obtaining K shortest paths corresponding to the virtual link; calculating the mapping probability of every shortest path according to the frequency spectrum bandwidth of every shortest path, determining the path with the maximum mapping probability; distributing frequency spectrum resource to the virtual link in certain modulation format on the path with the maximum mapping probability. Through the method of the invention, coordinate virtualization of the application resource and the bandwidth resource can be realized; after partial traffic is dredged, uniform mapping is carried out; the resource blocking rate is effectively reduced; and the service acceptance ratio is improved.