When the main distribution board loses power, the contact switch between the emergency distribution board and the main distribution board will be opened automatically; the emergency generator will start automatically within 45s, and the main switch of the emergency generator will be closed automatically; When the power supply of the main distribution board is restored, the main switch of the emergency generator is automatically opened, and the contact switch between the emergency distribution board and the main distribution board is automatically closed. After the main switch of the emergency generator is opened, the emergency generator will be automatically stopped after a delay of 10 minutes. The distribution board can realize the short circuit protection, overload protection and under voltage protection of the generator, and has the functions of automatic starting, power supply, opening, shutdown, fault alarm, etc.