The invention discloses an auto-switch-on device on the basis of power grid dispatching and an implementation method thereof. The system comprises a power grid dispatching automation sub-system, an auto-switch-on sub-system and a transformer substation monitoring sub-system, and is characterized in that the power grid dispatching automation sub-system is connected with the transformer substation monitoring sub-system via a communication network; and the transformer substation monitoring sub-system is connected with the auto-switch-on sub-system via a computer cache. The system and the implementation method of the invention can fulfill the functions of auto-switch-on and overload cutoff between and in the transformer substations and substitute for various existing auto-switch-on devices and systems which are already in use, thereby reducing the construction cost of the power grid, effectively improving the operational reliability thereof and guaranteeing the reasonable load distribution thereof.