为了解决目前大型游乐设施中的轴、销轴的免拆卸无损检测问题，根据该类零件使用中的特点，采用小角度纵波探头，在轴的两个端面实施检测。通过大量的实验，依据被检测轴的长度及端面尺寸，制作了实物试块并确定了探头的类型、参数(频率、角度、形状)及适用范围。验证了利用小角度纵波探头免拆卸超声检测轴类零件表面横向缺陷的可行性。

To overcome limitations faced by nondestructive testing equipment and technology for detecting axis and dowel axis of large Game Equipment without its disassembling, according to the using characteristic of this kind of accessory, and using the experience of domestic and overseas research results for reference, smallangle longitudinal wave probe is used to detect in both end surface of the shaft. By doing same sample and a lot of experiments and according to the length and side surface dimension of the detected shaft, the probe kind, parameter(frequency, angle, shape) and applicable scope were deduced for ultrasonic test method. The feasibility research on detecting surface horizontal crack flaw on axis by using smallangle longitudinal wave probe showed that flaws in shaft accessories could be detected by using ultrasonic test without them being disassembled.