Abstract: To describe 3D ship hull surface precisely and provide simulation help for charging-discharging of awkward length cargo, this paper proposed NURBS (Non-Uniform Rational B-Spline) based method to reconstruct 3D ship hull surface. Based on the study of basic theory of NURBS curve and surface modeling, many algorithms for NURBS such as the highly effective fast algorithm for calculating B-spline basis function, NURBS curve degree elevation algorithm based on end point interpolation are realized. A new method is further proposed to reconstruct NURBS surface by transfiguring fore and aft cross section line according to the hull lines plan or two-dimensional offset table. This method makes transfiguration to the cross section line situated at the bulb-bow and bulb-stern of the vessel, so that the projection of transfigured cross section line on the middle vertical section will be a curve and of isometry with the corresponding fore and aft contour line in broad sense, then a rectangular lattice will be formed by unified processing of these transfigured cross section lines together with other cross section lines and eventually a single hull NURBS surface will be reconstructed by using the end interpolation method. A simulation system is developed based on the proposed method and applied to awkward and length cargo charging and discharging. Compared to traditional modeling methods, this new simulation system can provide quick and precise loading scheme for shipping business.