In the imaging process, aiming at the problem that the scattering of multi-frequency laser pulse will make the image fuzzy and lead to the ambiguity of small features, a small feature enhancement method under multi-frequency laser pulse is proposed. The super-resolution image is reconstructed by using the least weighted square filter, the reflection component is calculated by the enhancement function of edge preservation, and the image enhancement coefficients of each image block are calculated, and the adjacent image blocks are merged by block difference factor. The parameter information of each pixel is obtained through the interpolation of enhanced parameters of super-resolution image blocks, and then the small features of the image are enhanced. The experimental results show that the maximum PSNR value of the proposed method is 32.1 dB, the color information retention rate is 0.82 to 0.93, the information entropy is up to 9.997, the SSIM is up to 0.982, and the small features enhancement effect of super resolution images is good.