In this study, we propose an active polarization imaging method based on laser illumination to tackle the issue of low target detection contrast in strong light backgrounds, which is a challenge in conventional photoelectric detection. Through constructing a laser incident bidirectional reflection distribution model, a laser incident polarization bidirectional reflection distribution model and a target surface polarization model of laser illumination, the coupling relationship between the polarization characteristics of three typical target materials and the divergence angle of a laser beam is analyzed. Backlight observation experiments are conducted in a controlled darkroom to verify the impact of the scattering angle of the laser beam on the polarization characteristics of the target. The experimental results show an 86.11% increase in target contrast for active polarization imaging under strong light background compared to traditional passive intensity imaging. Additionally, the visible polarization characteristics of different target materials vary with different divergence angles, and the line polarization of metallic materials is higher than that of non-metallic materials. The experimental results are in good agreement with the theoretical analysis. The outdoor solar backlight observation experiment verifies the applicability of the research method in high-intensity light and long-distance settings. This study can lay a theoretical foundation for improving accurate target perception under a strong light background.