Abstract: To efficiently generate contours from a large amount of bathymetric data, a fast algorithm of depth contours generation is proposed based on sorting the endpoints of segments in triangulation network. Firstly, the modified partition rules considering navigation security are proposed to optimize Delaunay TIN, in order to resolve the ambiguity problem caused by partition rules in the process of generating depth contours. Then, as the contour segment in each triangle which has isocenter is generated, the depth contours are progressively generated by sorting the random endpoints of contour segments. The experiment results show that the proposed algorithm can efficiently generate safety depth contours which can correctly present seafloor terrain, and has high efficiency in the situation of a large amount of bathymetric data.