以往所采用的圆域扇形柱体近区地改方法,都存在一定的局限和不足,它们难于模拟复杂地形,因而精度较低。本文提出方域近区地改的多面体解析法,采用三角形拟合地形,地改域为方形,使计算精度大为提高,且计算易于实现。文中还给出了几个对比实例,说明本方法比圆域扇形近区地改的精度至少可提高10倍以上。该方法也可适用于中远区高精度地改计算。 In the past, the methods of near-field modification of circular sector-shaped columns have some limitations and shortcomings. They are difficult to simulate complex terrain, so the accuracy is low. In this paper, we present a polyhedron analytical method for the transformation of a square area near the area. Triangulation is used to fit the terrain and the square area is changed to a square so that the calculation accuracy is greatly improved and the calculation is easy to implement. Several comparative examples are also given in the paper, which shows that the accuracy of this method can be improved by at least 10 times compared with that of circular sectors. The method can also be applied to the calculation of high accuracy in the distance area.