With the rapid development of intelligent technology, sensing technology, digital communication technology and virtual reality technology etc, the research for air-combat UAV ushered in a rare opportunity. The UAV Air-Combat Decision problem has become one of the research focuses of the military field in the world. Firstly, this paper analyzes the specific process of the UAV Air-Combat Decision and divides it into four decision-making phases. Secondly, the paper introduces the research status and the decision-making methods of the various phases, to further analyze the UAV Air-Combat Decisions. Finally, the paper analyzes in detail the difficulties and the research trends of the UAV Air-Combat Decision in the future.