The invention discloses an automatic induction system and a method thereof applied to kitchens or lavatories. The automatic induction system comprises an ambient light inductor for detecting ambient light intensity on peripheries of equipment in the kitchens or the lavatories, an approaching inductor for detecting whether the equipment in the kitchens or the lavatories are used by people, and a controller for controlling the equipment in the kitchen or the lavatories to execute corresponding actions according to a detection result of the approaching inductor, wherein the controller starts the approaching inductor for detection according to the variable quantity of the ambient light intensity. Therefore, the automatic induction system can realize low power consumption, is more energy-saving and has more accurate detection.