本文通过对钢制球形容器对接焊缝常见裂纹的分析,介绍用“端点回波峰值法”和“差值法”测定面状缺陷高度的原理和方法。测定了取向、大小、表面粗糙度不同的线切割槽、人工裂纹和实际裂纹的高度,确定了这种方法的适用范围和探测精度,为球形容器的裂纹测定,提供了简单实用的方法。 In this paper, the principle and method of determining the height of planar defects by “peak echo method” and “difference method” are introduced by analyzing the common cracks in butt weld of spherical spherical vessels. The line, the size and the surface roughness of the wire cut grooves, the artificial cracks and the actual crack height were determined. The application range and detection accuracy of this method were confirmed. The method provided a simple and practical method for the determination of the crack in the spherical container.