Software-defined network (SDN) promotes the development of the traditional network. The introduction of SDN into the space-ground integrated network can greatly mobilize the resources of networks at all levels. At the same time, it can realize intelligent management and control of the space-ground integrated network. Firstly, this paper introduces the space-ground integrated network and software-defined network, and discusses the research status of the space-ground integrated network architecture based on SDN. Then, the performance index of the SDN controller is introduced, the current SDN multi-controller deployment method is compared, and the controller deployment strategy of the SDN based on the space-ground integrated network is summarized. Finally, the future deployment method of SDN based on the space-ground integrated network controller is prospected and summarized.