A method for signal denoising is presented based on stage-combined discrete wavelet transform.Firstly

one scale of discrete wavelet transform（DWT） is used to obtain discrete approximation coefficients and discrete detail coefficients to noisy signal.Secondly

one scale of DWT and four scales of DWT are applied to the obtained discrete approximation coefficients and discrete detail coefficients

respectively.Thirdly

three scales of DWT are applied to the obtained discrete approximation coefficients and discrete detail coefficients from above the approximation coefficients

respectively.Finally

signal reconstruction is obtained after thresholds processing is done to all the decomposed wavelet coefficients.Experimental results show that the proposed method performs better than DWT and WPD for signal denoising under the same decomposed wavelet levels.