取样定理是“信号与系统”、“数字信号处理”等课程的重点和难点之一。本文针对大多数教科书对于取样定理的推导过程不够完整,造成学生理解困难的问题,通过两种方法对取样定理的原理进行了详细推导,降低了学生理解的难度,提高了教学质量,取得了较好的教学效果。 The sampling theorem is one of the key and difficult points in the course of “Signal and System”, “Digital Signal Processing” and so on. In this paper, most of the textbooks for the sampling theorem of the derivation process is not complete enough, resulting in students to understand the problem of difficulty, through two methods of the principle of sampling theorem deduced in detail, reducing the difficulty of students to understand and improve the quality of teaching, and made more Good teaching effect.