1. An inter-domain virtual network mapping method, performed by a server of a virtual network provider and comprising: receiving an inter-domain virtual network request; obtaining a latest physical network architecture information of each of N network domains; calculating an optimized mapping solution according to the latest physical network architecture information of the N network domains to divide an inter-domain virtual network into N virtual sub-networks, each virtual sub-network corresponding to one of the N network domains, the optimized mapping solution making a sum of a mapping price of all virtual nodes of the inter-domain virtual network and a mapping price of all virtual links of the inter-domain virtual network minimum; sending each virtual sub-network to a corresponding network domain thereof and performing a mapping in each network domain; initializing SUM=0, traversing each network domain and receiving a result of the mapping in each network domain, and updating SUM according to the result of the mapping in each network domain, wherein updating SUM according to the result of the mapping in each network domain comprises: determining whether the mapping in each network domain is successful; if yes, making SUM=SUM+1; if no, making SUM unchanged; determining whether SUM is equal to N; if yes, instructing each network domain to distribute a physical network source for the inter-domain virtual network request; and if no, instructing each network domain to maintain current status.