The invention provides a target saliency detection method for rainy day images. The method comprises the following steps: S1, extracting visual saliency based on luminance and color features, calculating luminance saliency map Slc; S2, extracting visual saliency based on color difference features, and calculating color difference saliency map Scv; S3, extracting the visual saliency based on the dark channel, and calculating the saliency map Sd of the dark channel; S4, mixing the brightness saliency map Slc, the color difference saliency map Scv and the dark channel saliency map Sd to obtain the final saliency map Sfinal, Sfinal=Slc. * Scv-Sd. In the invention, the brightness and color characteristics, the color difference characteristics and the dark channel characteristics of the target in the rainy day image are utilized to extract the saliency characteristics of the target in the rainy day image and construct a target saliency detection model, thereby providing an effective preprocessing method for the image sharpening and the detection of the target in the rainy day.