At present, the level of ocean submerged oil research and control is still low, especially for detecting the distribution information of submerged oil within 30m, the main reason is the lack of fast and effective detection methods. The Beijing Research Institute of Telemetry developes a prototype of underwater detecting lidar, by using the good transmission characteristics of laser in seawater, it can be used for submerged oil detection, and for high-precision detection of other objects like seabed. The prototype carried out the simulated detection test of the submerged oil in the pool, collected and analyzed the typical laser echo signals of the samples, and measured depth. The results are basically in line with the designed expectations, which lays a good foundation for further improving the submerged oil detection capability of lidar.