above all, this paper work on the principle of simulink . principle of block and model are explained during initialization and execution stage . then runge-kutta ( 4, 5 ) formula which is a main numerical integration method of simulink and zero crossing detection function are analyzed 从构成模型的基本单元??模块入手,阐述其运行机理并对模型的执行阶段进行全过程分析,然后介绍simulink的主要数值积分方法??四?五阶变步长runge-kutta法的基本积分原理,以及simulink的拐点处理功能??过零点检测技术(zerocrossingdetection)的基本原理。