This paper introduces a new method of data sampli ng and fault character extracting used in online fault diagnosis of cnc machine to ols spindle . a method of order ratio analyzing with variable turning angle was a dvanced . the data sampling circuit needed in this analyzing method was introdued in detail and the structure of the program was explained briefly 介绍了一种用于cnc机床主轴故障特征提取和数据采集的新方法，提出用可变回转角度阶比分析方法进行故障诊断，并详细介绍了所需的数据采集电路和程序结构。
