To effectively remove salt and pepper noise in digital images and improve image quality, a new algorithm for removing sa lt an d pepper noise is given based on the analysis of some typical removing noise me t hods. Firstly, according to the characteristics of salt and pepper noise，a nois e detection algorithm, which is based on dynamic window and the neighborhood pix els statistical information, is designed. The noise and the non-noise are effectively distinguished. And then, the noise is r emov ed by using improved adaptive median filter algorithm, in which the adaptive window size and the filtered val ue optimization strategy are introduced. Experimental results show that this me thod can not only remove salt and pepper noise in images, but also effective l y protect the details of image features. The algorithm is better than other methods for the image with high density of noise.