与标准的傅里叶变换相比，小波分析中使用到的小波函数具有不唯一性，即小波函数 具有多样性。小波分析在工程应用中，一个十分重要的问题就是最优小波基的选择问题，因为用不同的小波基分析同一个问题会产生不同的结果。目前我们主要是通过用小波分析方法处理信号的结果与理论结果的误差来判定小波基的好坏，由此决定小波基。常用小波基有Haar小波、Daubechies(dbN)小波、Mexican Hat(mexh)小波、Morlet小波、Meyer小波等5种。-Compared with the standard Fourier transform, wavelet analysis using the wavelet function has not unique, ie wavelet function with diversity. Wavelet analysis in engineering applications, a very important issue is the optimal choice of wavelet problem because different wavelets analysis of the same problem will produce different results. At present we are mainly through the error processing results with the theoretical results signal using wavelet analysis method to determine the quality of wavelets, which determines the wavelets. Haar wavelets have used wavelet, Daubechies (dbN) wavelet, Mexican Hat (mexh) wavelet, Morlet wavelet, Meyer wavelet five species.