The principle of relay protection belongs to a course of electrical engineering and automation specialty. Relay protection is one of the strongest disciplines in Huadian, and it is the top in China and even in the world. However, when the college entrance examination is accepted, electrical unification is enrolled according to a large category, that is, electrical engineering and its automation. It was not until my junior year that I divided the direction, including relay protection, power system and its automation, high voltage and insulation technology. However, it is obvious that undergraduate employment has obvious advantages in power system and its automation.