In order to enable the UAV to effectively avoid the sudden threat of the ground fire, this paper studies and uses the cognitive decision of human intelligence. By analyzing the ground attack process of UAVs, a ground attack model is established, and the maneuver behavior of UAVs during ground attack is summarized into three ways. The three way decision theory is to utilize the cognitive thinking of human brain for describing. A three way decision making method for cognitive decision making of UAV ground attack is presented. Through comparative analysis and simulation experiments with other types of autonomous attack decision making methods, the method enables the UAV to reasonably evade the threat of an air defense fire unit that suddenly appears during the attack process.