Spilled oil is one of the most serious marine environment disasters, which damaged ecological environment seriously with long-term and large-scale impact. On the other hand, since the density of oil spills increases at a low temperature, high pressure and deep sea conditions, oil spills can not rise to the sea surface. They suspend underwater. Therefore, based on the experiments and research in the Canadian Centre of Environmental Technology, an experiment is taken to detect the underwater suspended oil-spills by 532nm Lidar. In this experiment, 532nm green laser is used for detecting the underwater suspended oil spills. It can detect underwater oil slick at more than 290cm from the water. The experiment points out the way towards detecting underwater oil at 2m from the surface of the water and solves a key problem for underwater oil detection by Lidar.