The invention discloses a self-adaptive software-defined space-ground integrated network system. According to the technical scheme, the self-adaptive software-defined space-ground integrated network system is characterized by comprising a ground data center and a space part; the space part comprises a low earth orbit satellite (LEO), a medium earth orbit satellite (MEO) and a high earth orbit satellite (GEO); the system also comprises a software defined network (SDN). The software defined network (SDN) separates a control plane from a data plane, is suitable for multi-level satellites adoptingLEOMEOGEO architecture, is suitable for more types of constellations (satellite systems), such as Iridium constellations, compared with the design in the prior art, the system is better in universality. According to the system, the types of the service flows can be automatically detected after the initial model is set, and compared with the prior art, QoS parameters do not need to be manually input, so that the use convenience is greatly improved, and the practicability is higher. According to the system, after the service flows are classified, a more appropriate scheduling algorithm can be selected according to the service types, the overall resource utilization rate and QoS satisfaction rate of the system are improved, and the overall performance effect of the system is improved.