High accuracy surface modeling（HASM）constructed based on the fundamental theorem of surface is more accu-rate than the classical methods.However

because of boundary error

location error

etc

HASM has a big accuracy loss in real-world examples.In former researches we solved the location error with Taylor expansion.In order to reduce the HASM boundary error and improve its accuracy further

this paper presents a new method of Laplace interpolation to compute the re-gion boundary value.Gaussian synthetic surface and the real world test region are employed to validate the efficiency of this method.Results show that the boundary value computed with Laplace interpolation is more accurate than the classical methods

which can be regarded as an alternative for boundary value computation.