首先介绍了机械装备失效断口的三要素以及各种断口的基本形貌特征。然后, 对于断口分析技术, 从断口试样的获取方法到断口分析使用的仪器均进行了详细的介绍, 并对断口的宏观分析及微观分析的内容、任务进行了详细归纳和总结；同时举例说明了通过对断口进行深入细致的宏观、微观分析, 可以判断裂纹扩展方向、断裂源位置、断裂性质, 甚至构件的二级失效模式。最后列举了几个失效分析案例, 来说明断口分析技术在整个失效分析中所起的重要作用。

Firstly, the three elements of mechanical equipment failure fracture and the basic morphology characteristics of various fractures were introduced. Then, the fracture analysis technique was introduced in detail from the acquisition methods of fracture specimens to the instruments used for fracture analysis. The contents and tasks of fracture macro and micro analysis were summarized. It was exemplified that thorough and detailed macro and micro fracture analysis could help to determine the crack propagation direction, fracture source position, fracture property and second-order failure mode. Finally, some failure cases were cited to show the importance of fracture analysis technique for the whole failure analysis.