In the Internet of Vehicles (IoV) environment, the frequent changes in network topology are caused by the high-speed movement of vehicles, the diversity of road layouts, and the limited transmission range of vehicles. Therefore, selecting appropriate routing to ensure robust communication between vehicles is one of the main challenges in IoV. This paper focuses on the research of routing protocols in urban IoV scenarios. By integrating the IoV and software-defined network (SDN) architectures, a software-defined vehicular network architecture is constructed to enhance the reliability and efficiency of information transmission between vehicles. Utilizing the global view of the central controller, this study applies more vehicular information, including link stability, node congestion degree, and packet congestion degree, in route selection to improve path performance. Additionally, to address various complex scenarios in IoV, this paper proposes different deployment strategies, including proactive strategy, proactive-optimization strategy, and proactive-restriction strategy, to flexibly cope with complex scenarios and enhance the quality of communication services. Simulation results indicate that compared to the original passive strategy, the proactive-restriction strategy reduces end-to-end delay by 19%, increases delivery rate by 14.1%, and decreases the number of control messages by 39.8%.