The overgreat power of side lobe of frequecy spectrum of DMT signal will decline the transmission performance of system in the case of noise environment and channel variationsThe discrete wavelet(DWMT)is adopted to substitute the discrete Fourier transform in DMTThe transmission performance of the system is improved by carefully designing the spectral characteristic of modulation signalThis paper introduces the basic principle of DWMT and analyzes the key techniques of DWMT(bit loading algorithm,baseband filter design,etc)This paper demonstrates that DWMT is superior to DMT in performance by making a comparison in performancee between them and that DWMT Technique has potentialites in broadband access network