Abstract: High accuracy surface modeling(HASM) technique is designed to improve accuracy in surface fitting,based on the surface theory.However,the constraints imperfection in the model led to deviation and the integral iterative algorithm adopted in HASM technique resulted in high computation complexity and huge memory usage usually exceeding the PC capacity,so that it became difficult to put HASM technique into application.So an innovative model is put forward based on the sequential least square in computation on the basis of independent units.The technique applies sequential division to computation,which can divide equations into groups to process in sequence.Cross-validation has indicated that HASM-AD technique excelled other spatial interpolation techniques in accuracy.Simultaneously,the studies has demonstrated that the HASM-AD algorithm has prominently reduced the computation complexity,relieved memory usage and effectively broken up the restriction from the extent of data sets on computation.