To address the problem of 16-line lidar sparse point clouds and poor perception algorithm due to the distant port sea surface targets, a dynamic and static target detection method IMU is proposed. Firstly, we propose an improved Ray Ground Filter algorithm for sea clutter filtering to address the problem of false detection caused by the point clouds of unmanned vessel wake stream; then, we propose a target clustering algorithm for different distances to address the problem of poor clustering due to different sparsity of target point clouds; finally, we realize inter-frame projection of lidar point clouds by fusing IMU to complete the dynamic-static target detection and key point prediction. By using the unmanned vessel experimental platform and the simulation platform for target detection experiments, the algorithm in this paper has high detection efficiency and stable robustness, which can better achieve the perception of port environment by unmanned vehicles.