Along with the rapid economic development, industrialization and urbanization construction acceleration, the power demand is also increasing. The grid power supply ability and reliability of regional development of social economy is extremely important. Substation in power system is one of the indispensable important link, its power conversion and electrical power for the redistribution of heavy tasks, the safety and economical operation of power grids play a pivotal role. The transformer substation design must reflect socialist technology economic policy, conform to the safe and reliable, advanced technology, reasonable economy and ensure quality requirement, in this design fully embodies the these requirements. This thesis mainly is a part of the electrical design instructions, and its content requirements: 1) substation the main electrical wiring design; 2) electricity wiring design; 3) short-circuit current calculation; 4) the main electrical equipment selection; 5) substation electrical general layout; 6) with the relay protection Along with the rapid economic development, industrialization and urbanization construction acceleration, the power demand is also increasing. The grid power supply ability and reliability of regional development of social economy is extremely important. Substation in power system is one of the indispensable important link, its power conversion and electrical power for the redistribution of heavy tasks, the safety and economical operation of power grids play a pivotal role. The transformer substation design must reflect socialist technology economic policy, conform to the safe and reliable, advanced technology, reasonable economy and ensure quality requirement, in this design fully embodies the these requirements. This thesis mainly is a part of the electrical design instructions, and its content requirements: 1) substation the main electrical wiring design; 2) electricity wiring design; 3) short-circuit current calculation; 4) the main electrical equipment selection; 5) substation electrical general layout; 6) with the relay protection