Abstract: According to the noise characteristic and application requirement of Computed Tomography（CT） slice image, the denoising algorithm based on Lipschitz exponent and Stationary Wavelet Transform（SWT） is proposed. This algorithm uses the improved median filter for filtering the impulse noise, then based on the relationship of Lipschitz exponent of step edge and wavelet coefficient and under the premise of protecting the image edge details, the threshold denoising method based on SWT for filtering Gaussian noise is adopted. The experimental results show that whether the visual effects or the perfomance of the minimum Mean Square Error（MSE） and the Peak of Signal-to-Noise Ratio（PSNR）, and protecting the image edge details of this algorithm have great improvement.