数字滤波器是数字信号处理的重要环节，数字滤波器可分为IIR和FIR两大类。本文介绍了IIR和FIR的基本设计原理以及在MATLAB环境下如何利用直接程序设计法、SPTOOL设计法和FDATOOL设计法给出IIR和FIR数字滤波器的设计方法和操作步骤，并给出设计设计实例及运行结果，同时利用MATLAB环境下的仿真软件SIMULINK对所设计的滤波器进行模拟仿真，仿真结果表示设计参数设置合理。-The important aspect of the digital filter is a digital signal processing, digital IIR and FIR filter may be divided into two categories. This article describes the basic design principle of IIR and FIR, as well as how to use the MATLAB environment direct programming method the SPTOOL Design Law and FDATOOL of design method given IIR and FIR digital filter design methods and steps and design design example is given and operating results, while taking advantage of simulation software SIMULINK MATLAB environment of filter design simulation, design parameters set reasonable simulation results indicates.