The sun glint is caused by the mirror reflection of sunlight from the sea surface. The high radiation intensity of glint saturates the sensor pixel, making the contour of the target on the sea surface lost in the sun glint, which affects the detection of the target. A method for suppressing the sun glint is proposed based on the polarization time-domain characteristics of the sun glint. The method uses the real-time polarization imaging system to polarized radiant sea surfaces in real-time and to obtain the polarization video information along three polarization directions of 0°, 45°, and 90°. Stokes vector is calculated according to the corresponding frame image with different polarization directions, and the sequence of spatial-domain glint-suppression polarization-radiation patterns is generated. The generated image sequence is fused in the time domain to suppress the sun glint. In this study, a real-time surface polarization imaging observation-experiment platform was built to conduct a detection experiment of the target surface under the glint background. The experimental results show that the signal to clutter ratio of glint suppression image obtained using the proposed method is improved compared with that of the ordinary linear polarization image; the glint suppression effect is obvious, and the saliency of the sea target in the image is enhanced.