The invention belongs to the technical field of ocean remote sensing monitoring and specifically a ship and wake mesh model merging and optimization method. The invention relates to computational fluid mechanic and computational electromagnetic technologies. The method comprises the specific steps of (1), determining an overlapping area of the ship model and the wake model through utilization of prior knowledge for ship and wake models; (2), solving intersection points of triangular surface elements of the ship model and the wake model in the overlapping area; (3), carrying out two-dimensional Delaunay partition on a scattered point cloud, thereby obtaining an initial mesh merging model; and (4), eliminating deformed triangular surface elements, thereby optimizing the mesh model. The merging test of a series of complicated models indicates that the algorithm provided by the invention is applied to the fusion of the mesh models of ship and rough sea surface, and ship and wake with different mesh densities and different structures. The algorithm can be operated stably without an additional condition, the number of the mesh units is reduced, and the deformed triangular surface elements are removed completely.