敌空袭目标主攻方向判断是作战指挥的重要依据。着眼于要地防空作战决策需求，分析了影响空袭目标主攻方向的9个重要指标，考虑到火力单元最小部署间距，运用灰色关联聚类方法，对空袭目标子方向进行合理划分；利用主成分分析法对影响指标降维处理，减少了指标间相关性和计算量，并建立了综合评价模型计算得出方向排序。算例结果表明，该方法正确可行。

The judgment about the main direction of the enemy air attack is very important for operational command. This paper focuses on the need of decision-making for air defense of critical area and analyzes the nine major indicators that affect the main direction of the air-raid target. With consideration of the minimum deployment spacing between the firepower units, the gray relational clustering method is used to rationally divide the sub-directions. The Principal Component Analysis (PCA) method is used for dimensionality reduction of the impact indexes, which reduces the correlation among the indexes and the calculation cost. A comprehensive evaluation model is built to calculate the sorting of the directions.The results show that the method is correct and feasible.