In order to solve the difficulty in analyzing the shaping law of NC-ECM with ball-end cathode, the method of processing simulation was presented based on the finite element method (FEM). The two-dimensional analysis model of the electric field with ball-end cathode built in ANSYS software was solved. The current density distribution and surface shape in different time on the anode were obtained. The experiments based on the simulation parameters were carried out, and the dimensions of the processed surface were measured, which were compared with the theoretical values. It is indicated that the simulation method meets the accuracy of the engineering calculations. The method and theory for further in-depth research on the process simulation in NC-ECM with ball-end cathode are provided.