Underwater imaging technology is one of the research hotspots in underwater exploration. According to the current problems of underwater imaging devices, a new target imaging and processing system is proposed. The imaging scheme, imaging principle, imaging analysis and processing algorithm are studied. Firstly, theoretical analysis and numerical simulation are carried out based on the Fresnel 's law. Specifically, the MATLAB software is used to simulate the reflection polarization characteristics, and the amplitude ratio and phase difference of two vertical components in reflected light are obtained. Secondly, in the case of liner polarized laser illumination, based on the Stokes imaging theory, the polarization information of the object is detected, and the Stokes parameters of the object are obtained. Finally, the polarization degree and polarization angle images are obtained and analyzed after being converted into HSV space and Lab space. The results show that the polarization degree and polarization angle images can highlight the material information, improve the contrast of different materials and make it more easier to be recognized by human eyes.