To verify the feasibility of detecting small targets in sea clutter with infrared polarization imaging, experiments are carried out on infrared polarization imaging against the sea background. Both an infrared thermal imager with a polarizer and one without a polarizer are used to detect the dim target against the sea clutter background. At the same time, the data under the corresponding condition are collected. To verify the effectiveness of the polarizer in the inhibition of sea clutter, imaging processing is performed for the collected data. The target is not extracted from the data collected by the infrared thermal imager without a polarizer. However, the target is extracted from the data collected by the thermal imager with a polarizer through image enhancement, median filtering and edge detection.