Abstract: According to image characteristics of laser active imaging, a new image denoising method is presented combining wavelet transform and median filter. After wavelet transform, high frequency sub-band images at horizontal, vertical and angular directions are denoised by three different filter templates. In order to protect edge information, edge detection is used to separate edge information from noises. Denoised-image was gained by composing the three high frequency detail images with mean filtering and low frequency approximation image. Experimental results show that this method can remove the noise of image effectively. Meanwhile, the detail of the image is kept well and the de-noising effect is better.