Abstract: This paper introduces the main forms and detection methods of leakage in construction underground project, and analyzes the principle of infrared thermal imaging technology in detecting leakage in underground construction. The experimental results show that infrared thermal imaging technology can not only quickly locate the water leakage point, but also clearly show the area range of the water leakage point, which greatly improves the efficiency and scientific nature of water leakage point detection. The research results can provide reference for the personnel who use infrared thermal imaging technology to detect water leakage in construction underground project.