As the absorption and scattering of light in underwater propagation,p roblems such as fuzzy,low contrast,color deviation and uneven illumination appear in underwate r images taken.In view of the above problems,an improved underwater enhancement algorithm based on Gamma correction and multi-scale fusion is proposed.Firstly,Red and Blue channels a re compensated based on Green channel,and the correction image is obtained by Gray World algorithm after histogram stretching of RGB three channels.Then,the color corrected image is corrected f or uneven illumination by using the improved Gamma function to obtain the uneven illuminat ion corrected image,and the illumination uniformity image is normalized.Then,the contrast of t he image after uneven illumination correction is improved by contrast limited adaptive histogra m equalization (CLAHE) algorithm to obtain the contrast improved image.Finally,the multi-scale fusio n algorithm is used to fuse the above three images to obtain the enhanced image.Experimental results s how that the proposed algorithm has good processing effects on images in different underwater environments,and the image quality evaluation index is significantly improved.