The invention discloses a method for remapping resource demand dynamic change based on a virtual network, relating to the internet technical field. The method comprises the following steps of: establishing a physical network model, a virtual network model and a physical network available resource model; according to the physical network model and the virtual network model, establishing the original virtual network mapping model; according to the physical network model and the original virtual network mapping model, determining available physical network resources; for the resource demand dynamic change of the virtual network, clearly determining a virtual node and a virtual link to be remapped; determining an order for joining the remapping process of the virtual node to be remapped; according to the order, completing the node mapping and the relative link mapping to the virtual node to be remapped; and updating the available physical network resources. The method disclosed by the invention aims to achieve an optimization purpose of minimum resource consumption, and therefore, the resource cost of each virtual network in the remapping process can be minimized so as to accord with the actual situation.