Construction method for digital elevation model for discrete expression of landform on earth surface

The invention discloses a construction method for a digital elevation model for discrete expression of landform on the earth surface. The construction method comprises the following steps of: extracting elevation values of sampling points from the original data of the earth surface and performing spatial discretization on the elevation values to generate a plurality of landform curved surface grid points of the known elevation values of the sampling points; solving the elevation values of the landform curved surface grid points of non-sampling points; calculating first fundamental quantity and second fundamental quantity of each landform curved surface grid point according to the elevation values of all landform curved surface grid points and establishing a landform curved surface equation set by using a Gauss equation and elevation sampling points; solving the landform curved surface equation set by using a Gauss-Seidel iterative algorithm, wherein a simulation result of the digital elevation model is obtained after each iteration is finished; judging whether the simulation result of the digital elevation model meets the accuracy requirement; if the simulation result meets the requirement, stopping the iterative computation and outputting a group of ordered values to express the digital elevation model of a ground elevation entity in an array form, wherein the digital elevation model is used for the discrete expression of the landform on the earth surface; and if the simulation result does not meet the requirement, repeating the iterative computation.