Abstract:In recent years,with the construction of smart substations,the equipment based on digital circuits is extensively used,which proposes higher requirements for the anti - interference ability of secondary system. A reasonable equipotential grounding mode of secondary system is particularly important. he research status of laying methods for equipotential ground screen of secondary system is summarized,covering the overall laying principle of equipotential ground screen,the common problems of laying indoor and outdoor equipotential ground screen,and the connection between equipotential ground screen and main grounding grid. Finally,the existing problems and future research directions are analyzed.