结合数学上关于圆的对称点的概念,利用几何作图的方式处理了和镜像法有关的典型的电学问题——接地导体球问题,第一,简洁准确地找到像电荷的位置,并计算其电荷量;第二,作出了两个不等量异号点电荷的零势面. Combined with the mathematic theory about the symmetry point of a circle, we deal with the problem of ground conductor ball, which is a typical electrical problem related to the image method by means of geometric mapping. First, we find the charge-like location concisely and accurately and calculate its The amount of charge; secondly, we made two zero-potential points of unequal-point odd-point charge.