The invention relates to a circular-arc grid subdivision method used for electrical tomography sensitivity coefficient solving. The method comprises the following steps of determining a concentric circle number N of a subdivision circle field domain and a radius number M of an equally-divided circle, wherein the M is an integral multiple of the number of electrodes in an electronic imaging system; acquiring a concrete coordinate of each pixel in a detected area; based on a subdivided circular-arc pixel and according to a traditional method, solving a sensitivity coefficient of a first electrode pair relative to other electrode pairs, rotating an acquired result and acquiring residual sensitivity coefficients so that a sensitivity coefficient matrix can be obtained. A computation complexity of a sensitivity matrix is reduced and a speed of reconstructing an image can be increased.