Abstract: The accuracy and readability of underwater contour maps are of great significance for hydrological management, hydraulic engineering, and navigational safety.To address issues in existing isobath generation methods, such as insufficient precision, unrealistic rendering effects, and excessive manual editing requirements, we propose a new isobath optimization and editing method.This method generates initial isobaths through linear interpolation to construct triangular networks, and then applies iterative optimization through control point movement and polygon smoothing techniques to achieve automatic smoothing of isobaths.Experimental results demonstrate that this method shows good adaptability under different scale conditions and complex terrain environments.The optimized isobaths are smoother and more fluid, effectively avoiding sawtooth patterns and irregular protrusions while strictly maintaining the positions of underwater topographic feature points.Compared with traditional isobath optimization software, this method significantly reduces processing time from raw depth data import to final isobath generation, and notably improves the quality and efficiency of isobath editing and optimization.The research provides reliable technical support for underwater surveying and hydraulic engineering planning, with practical significance for enhancing the accuracy and smoothness of underwater topographic representation.