介绍了机械产品故障分析的基本知识和概念： 材料老化和表面层变化是引起机械产品损坏的两个主要故障机理；引起表面层变化的原因有表面层分子与原子状态、工艺过程及使用过程等因素；老化是一个复杂的物理与化学过程，其损伤模式有疲劳、变形、腐蚀、粘附及表面磨损等。材料损伤分深度和表面两类，且有定量估计与输出参数两种估计方法；老化是一个多阶段过程，且呈随机性；表面层特征参数包括几何、应力、表面层结构和吸附膜结构等参数 The basic knowledge and conception of failure analysis of mechanical products are introduced: material aging and surface layer change are the two main failure mechanisms which cause the damage of mechanical products; the reasons of surface layer changes are the surface layer molecules and atomic states, the process and the use process Factors; Aging is a complex physical and chemical process, the damage patterns are fatigue, deformation, corrosion, adhesion and surface wear. The material damage is divided into two types according to depth and surface, and there are two estimation methods: quantitative estimation and output parameter. Aging is a multi-stage process with randomness. Surface layer parameters include geometry, stress, surface layer structure and adsorption film structure parameter