This study proposes an underwater enhancement algorithm based on color balance and multi-scale fusion to address the color deviation， detail blur， and low contrast of underwater images caused by water absorbing and scattered light. A color balance method was used to correct color. Then， the color-corrected image was converted from the RGB space to Lab space， and the L-channel was processed with the contrast limited adaptive histogram equalization method to enhance the contrast. Subsequently， the image was converted back to the RGB space. Finally， the multi-scale fusion method was used to fuse the color-corrected image with the contrast-enhanced image according to weight maps. After image enhancement， the enhancement effect of the proposed algorithm was compared with that of other algorithms in terms of visual effect and image quality evaluations. Experiments show that the proposed algorithm can remove color deviation of an underwater image， as well as improve its clarity and contrast. Compared with the original image， the entropy， UIQM， and UCIQE of the processed image increase by at least 5.2%， 1.25 times， and 30.8%， respectively， thereby proving that the proposed algorithm can effectively improve the visual quality of underwater images.