The design mainly starts with the electrical design of electrical substation , combining with raw data, then complete the steps of substation design, including: full factory load statistics; high pressure into the line of choice; choose the number and capacity of substation transformers ; drawn sketch the whole plant distribution system; short-circuit current calculation; high and low voltage distribution equipment selection; high and low outlet options; protection devices to set their calculation; lightning protection and grounding; draw total electricity substation system-wide plan. In people-oriented objectives, the operation of substation requires reliability, security, flexibility and economy. Through the completion of the subject, to enhance the power supply works, power systems understanding and mastering the application of course in the process of design, to the practice of self-development, a wealth of knowledge, the purpose of consolidating the profession.