对高速电子束入射到试样表面时产生的一系列电子和光子信号进行了介绍，对透射电子、背散射电子和二次电子的衍射机理和成像机理，以及利用特征X射线和俄歇电子进行元素成分的定性和定量分析原理进行了概述，对透射电子显微镜和扫描电子显微镜的结构、工作原理、工作特性、试样要求及制样过程等作了较详细的描述，重点讨论了X射线能谱仪、电子背散射衍射仪以及俄歇电子谱仪在机械装备构件深层次失效机理研究方面的作用。实际应用表明：电子光学分析技术在机械构件失效分析中的主要应用是可以从深层次（可达到原子级别）研究构件失效的本质，包括材料的晶体结构、组分、表面微观形貌及各种特性等。

The series of electronic and photon signals produced by a high-speed electron beam incident on a sample surface were introduced. The diffraction mechanisms and imaging mechanisms of transmission electrons, backscattered electrons and secondary electrons, and the principles of qualitative and quantitative analysis of element compositions by characteristic X-ray and Auger electrons were explained. The structures, working principles, working characteristics, sample requirements and sample preparation processes of transmission electron microscope and scanning electron microscope were described in detail. The role of X-ray energy dispersive spectrometer, electron backscatter diffractometer and Auger electron spectrometer in the study of failure mechanism of mechanical equipment components was discussed. The practical application shows that the main application of electron optical analysis technique in the failure analysis of mechanical components was that it could study the essence of component failure from the deep level (up to the atomic level), including the crystal structure, compositions, surface micro-morphology, various characteristics and so on.