主轴是大型观览车结构中的重要部件，具有难以拆卸的特点，一旦发生故障，危险性极大。根据大型观览车主轴的结构特点，制定了相应的声发射检测方案，对在役观览车主轴中的异常声响进行了声发射在线检测，分析并给出了异常声响信号的声发射参数特征、定位特征和波形频谱特征，并对两个检验周期中声发射检测的结果进行了比较。结果表明，声发射检测技术可以用于大型观览车主轴运行状态的监测与评价。

As one important part of the giant wheel, the main spindle is difficult to be disassembled. While failure occurred on the main spindle, the risk is rather high. According to the structure characteristics of the main spindle on giant wheel, the method of AE testing was established, and the abnormal sound, which was produced by the main spindle, was detected on-line in this paper. The author acquired the AE characteristics of the abnormal sound, including AE location features, parameter distribution features and wave spectrum characteristics. Also, the twice results of AE testing in two test cycle were compared in the paper. The results indicated that the AE technique could be applied to the state monitoring and evaluation of the main spindle on giant wheel.