According to the characteristics of laser active imaging and the real time requirement，a new image denoising method is presented combining lift-wavelet transform and median filter.Firstly,the noise image is dealt with median filter.Secondly,the noise image is decomposed with the lift-wavelet.Finally,the high frequency parts of decomposed image are processed by the threshold function.The image signal to noise ratio（SNR）and the run time（T）and the image surface chart are applied to estimate the denoising effect of the laser images.The algorithm proposed is compared with the ordinary wavelet,the ordinary wavelet combined with the median filter and so on.Experimental results show that this method can remove the noise of image effectively.Meanwhile,the processing speed is faster.It can meet the requirement of denoise and real-time.