Usually, the value of a in this method is a subjectively given decimal, and can not offer optimal recognition results in varied clutter environment. A new a truncation set feature extraction based method with adaptive selection of a is proposed. 通常α截集特征提取方法中的α值是主观给出的一个小数,在多变的雷达杂波环境中不能使α截集特征提取方法给出最佳的识别效果。