Surge arrester are usually used in the substations to limit lightning overvoltage and protect equipment operation. According to the characteristics of 750kV substation system condition, single-line and layout of the substation, it is established by using electromagnetic transient calculation program-EMTP that the calculation model of lightning intrusion wave overvoltage of 750kV switchgear. By calculating the lightning overvoltage under different surge arrester configuration schem, the surge arrester configuration scheme which meets the equipment insulation requirements and has excellent economic effect is obtained. In 750kV substation, on the premise of setting a set of 600kV surge arrester in the main transformer circuit, it is proposed that 600kV surge arrester should be installed in the bus, main transformer and outgoing line circuit.