焊缝余高引起的非缺陷回波信号可能会出现在一次波声程以内，影响对缺陷回波信号的正确辨识。分析了一个可疑的回波信号，总结了一种正确辨识缺陷回波信号的方法。结果表明：该焊缝中的反射回波为非主声束轴线入射到内焊缝焊角上的反射回波，而非缺陷回波。当检测过程判断缺陷的信息量少时，发现可疑缺陷后，应首先对回波信息进行正确定位，不能确认是焊缝缺陷的情况下，可利用CAD等作图软件对超声检测的声束路径进行分析，辨别超声检测回波信号的真正反射面，从而对超声检测回波信号进行准确判断。

The non defect echo signal caused by weld reinforcement may appear in the first wave path, which affects the correct identification of defect echo signal. A suspicious echo signal was analyzed, and a method of correctly identifying defect echo signal was summarized. The results show that the reflected echo in the weld seam is the reflection of the non main acoustic beam axis incident on the inner weld corner, not the defect echo. When the amount of information in judgment defect in detection process is small, the echo information should be correctly located after the suspicious defect is found. If it can not be confirmed that it is a weld seam defect, CAD and other mapping software can be used to analyze the acoustic beam path of ultrasonic testing, identifying the real reflection surface of ultrasonic testing echo signal, so as to accurately judge the ultrasonic testing echo signal.