With the rapid development of mobile services, big data, cloud services, and artificial intelligence, traditional network services cannot no longer meet the requirements of current network development and solve the problems of the resource allocation and scheduling ossification in the current network. Therefore, by using network virtualization technologies, we can provide the flexible network resource configuration information for users to reduce network cost and improve network resource efficiency. The required bandwidth resources of each virtual link are divided into different transmission line rate by employing mixed line rate splitting. We propose an optimized cost approach for Virtual Optical Network (VON) mapping based on mixed line rate. Simulation results show that the proposed optimized cost approach of VON mapping based on mixed line rate can achieve better optimization and balance in terms of the network cost, frequency slot occupation, the configuration of optical transponders, and optical regenerators.