Abstract: Due to the absorption and scattering of light in water, as well as the difference in the propagation distance of light of different wavelengths, the underwater image was seriously affected by the contrast reduction and color bias, so the white balance correction of color was a key technology of underwater image processing. In this paper, a new ColorLess Constancy principle (CLC) and a white balance method were proposed. Firstly, we converted color images to YCbCr color space to achieve bright color separation, and then tested chrominance component calculation by means of nonlinear color of each pixel corresponding weights, and then according to the new linear weighted algorithm, calculated the chromaticity of each pixel to realize the protection of the colorless region in the image and the color correction of the biased region. Compared with several classical white balance methods, CLC method overcame the disadvantages of traditional methods that tended to produce bad color bias in colorless areas and achieves better visual perception effect. The experiment shows that the algorithm has low complexity and good robustness, which indicates the practicability of CLC white balance algorithm and the scientificity of the principle of colorless constancy.