The invention provides a potential distribution measurement method for a grounding electrode. The method comprises: according to the location and topographic condition of a grounding electrode, n measuring points from A1 to An are selected; distances xn between the n measuring points and the central point O of the grounding electrode are obtained respectively; two points with the distance of Ln in an OAn direction is selected by using the An as the center, a potential difference Un between the two points is measured, and a ground current Ic of the grounding electrode is measured; according to a maximum ground current Imax of the grounding electrode, potential difference conversion is carried out to obtain U'n; and on the basis of the U'n, potential values of the measuring points are calculated and a potential distribution map is obtained based on the potential values. According to the invention, the method has advantages of small measuring error, saved resources, high reliability and practicability.