本文从理论上推导出CRC 算法实现原理，给出三种分别适应不同计算机或微控制器硬件环境的C 语言程序。读者更能根据本算法原理，用不同的语言编写出独特风格更加实用的CRC 计算程序。-is theoretically derived from the CRC algorithm principle is given, respectively, to adapt to three different computer or microcontroller hardware environment of C language program. According to the readers better method, use different language unique style more practical CRC calculation procedures.