Abstract: In prophase of land consolidation, the high efficiency and rate of earthwork calculation is demanded. In the paper, based on the contour lines and elevation spots in relief map, the method of Triangulated Irregular Network(TIN) interpolation was utilized in interpolation of contour lines, the Digital Elevation Model(DEM) based on the contour lines after interpolation was built. And the earthwork was calculated in utilization of the DEM. In contrast to the survey value of 32 location points, the accuracy of DEM met the practical demands. The method of earthwork estimation is feasible.