Abstract: In view of current time-consuming and laborious methods of potato defect detection，expensive equipment and high magnetic field，an electrical resistance tomography method to detect potato defects were proposed and data acquisition method of potato defect resistance image field array was studied.Based on modeling of imaging physics，effects of different electrode shapes on the electrical potential characteristics of object field and isoline，as well as the simulation of shape of excitation electrode，electrode coverage and excitation mode were studied.Finally，the data acquisition mode of object field array was determined，and electrode structure was optimized.