In order to improve the detection and recognition ability of an electro-optical imaging system, a novel method for the target-background contrast enhancement based on color polarization imaging is proposed. Based on the Fresnel principle, the variation of target degree of linear polarization with wavelength of incident light is investigated. A collection of color polarization images under different rotation angles is conducted, which is separated into 0°, 45°, 90° and 135° polarization images within the red, green and blue channels. In addition, the polarization images within each channel are calculated, respectively. The red, green and blue polarization images from three channels are synthesized as a novel color polarization image, which contains richer image information than its original color image. A color polarization experimental setup is constructed. Two groups of experiments on target-background contrast enhancement are conducted, which take vector angle distance and contrast calculation as two objective evaluation indexes. The results show that this color polarization method can be used to increase the average distance of vector angle by 0.13 and the contrast calculation by 0.11.