FT是一种FT的高效算法，称为快速傅立叶变换（fast Fourier transform），它根据离散傅氏变换的奇、偶、虚、实等特性，对离散傅立叶变换的算法进行改进获得的。(FT is an efficient algorithm for DEFT, called fast U Lie transform (fast Fourier transform). It is obtained by improving the algorithm of discrete U Lie transform according to the odd, even, virtual and real properties of the discrete Fourier transform. fast Fourier transform algorithm can be divided into time extraction algorithm and frequency extraction algorithm.First,the basic principle of FT is briefly introduced.)