Combining computational fluid dynamics and optimization techniques provides a significant method for automatic multi-scheme selection in hull form optimization, which can improve the design level of energy-efficient ships. This paper focuses on hull surface automatic modification and its application in hull form optimization. A new hull surface automatic modification method is proposed, based on the radial basis function interpolation method. Furthermore, Delaunay triangulation is applied in order to determine the support radius of the Wendland basic function. The developed hull form optimization tool is applied to the hydrodynamic design optimization of a Series 60 model, and model tests are carried out on the original and an optimised model at WHUT (Wuhan University of Technology) for validation. The numerical optimization and model tests results demonstrate that the proposed method can significantly improve optimization efficiency.