The invention discloses a dark-channel-prior-method-based non-uniform-light-field underwater target detection image enhancement method. The method comprises: an original color image of a non-uniform-light-field underwater detection target is obtained, and a corresponding transmission graph is calculated by using a minimum value filter algorithm; the original color image is converted into an original gray-scale image and the original image is divided into a bright region, a normal region, and a dark region; illumination vectors of all regions are calculated; with a guiding filter method, a guiding filter output image of the original color image is calculated on the condition of the transmission graph; recovered enhanced images of regions, with different brightness values, of the original image are calculated; and quantitative evaluation is carried out on a dodging processing recovered image in terms of a mean value, a variance, a contrast ratio, and an information entropy until the recovered enhanced image meets an index requirement. According to the invention, because of the guiding filter method with illumination vector weighting, smooth balancing processing is carried out on regions with different brightness values, so that the overall coordination of the processed image is enhanced and the texture information is enriched.