Influenced by gun bore structure and illumination, the gun bore panoramic image has the problem of uneven illumination which will influence the quality of image segment. The de-background is adopted to eliminate the uneven illumination in gun bore images, and the homomorphic filtering based on wavelet is ameliorated through the bayesian shrinkage method. The high-frequency subband images of gun bore panoramic image are revised by weighting, and the low-frequency subband images are modulated linearly. The evaluation criterion for corrections of nonstandard images by different algorithms is proposed. Experimental result of the gun bore panoramic image shows that the modified algorithm can decrease the expense of marginal information, on the basis of improving the image quality primely.