Abstract: Abstract： The space-ground integrated network has the characteristics of large scale， complex structure， node exposure and dynamic topology. To ensure the security and efficiency of network handover of user nodes in the whole system， this paper proposed a new space-earth integrated network security handover architecture based on the idea of separation of control plane and forwarding plane in software-defined network. The function of each functional module of the application layer， control layer and device layer of the architecture is expounded in detail， to achieve the goal of safe handover， manageable and controllable， accurate and efficient， flexible and definable. According to the characteristics of the architecture， considering the handover reservation time and the related attribute values that affect the handover， a multi-attribute weight adaptive handover decision algorithm based on the received signal strength prediction is proposed. The experimental simulation results show that the handover decision is accurate and can meet the needs of the security handover of the space-ground integrated network.

Key words: Key words： space-ground integration network, software defined network （SDN）, security handover architecture, attribute weight optimization, handover decision algorithm