针对海底管道对接环焊缝全自动超声检测（AUT）中，分区法带状图测量缺陷长度存在误差的情况，使用不同方法对试块中已知尺寸的人工反射体进行测量，并与已知尺寸进行比较，计算误差值。通过数据分析，证明了采用试块误差值修正后的缺陷长度更加精确。该方法对接近标准允许的临界尺寸缺陷的评定起到了积极作用，可在一定程度上减小因缺陷长度评定造成的误判和漏判，提高了施工效率。

There is an error in the defect length by the zone discrimination strip pattern measurement in the Automatic Ultrasonic Testing (AUT) of the girth weld of the subsea pipeline. The artificial reflectors of known sizes in the test block can be used to decrease the error by using different methods and by the comparison of related error values. Through data analysis, it is proved that the defect length corrected by the test block error value is more accurate. It plays an active role in the assessment of defects close to the critical size allowed by the standard, which can reduce the misjudging and undetected defect caused by the defect length assessment to some extent and improve the construction efficiency.