It is not only important but also very difficult / this paper analyses the form and the feature and the expression of c language switch structure in executable file . a pattern . language is defined to describe the recognition pattern of switch structure boot . the design principle and the realization method are introduced about the recognition program and the recovery program of switch structure 本文分析了c语言开关结构在可执行文件中的形式、特点和表示;定义了一种模式语言,用以描述开关结构引导区识别模板;给出了开关结构识别程序和恢复程序的设计原理及实现方法。