From the analysis of modular arithmetic used in the higher dimensional Arnold cat mapping, and the application of modular arithmetic is to change a big number into a definite numerical range, so modular arithmetic is sensitive to the change of low-order digit. 高维Arnoldcat映射中的使用了模运算,由于模运算作用是将一个大数转化在一定的取值范围之内,所以模运算对低位的变化是很敏感的。