In this paper, the application of wavelet transform in image de-noise is studied. Via thresholding operation in wavelet domain of image, it can reduce noise effectively, and at the same time, with a little loss of image detail. Detail discussion of this wavelet thresholding method is presented in this paper, and some methods of threshold selection are also given. It has been proved that the wavelet thresholding technology is an effective method for image de-noise.