Under the network centric warfare, it is significant to perfect army combat system. Air-ground cooperative engagement with army aviation has been an important combating mode to form system operational capability. The air-ground cooperation contains two-level coordination, i.e. platform and element coordination, for different missions. In this paper, the primary architecture and key technologies for the air-ground cooperation are proposed by analysis on the requirements of applications, capacities and key technologies. The realization approach for future prospect is explored to build platform and element coordination gradually.