The invention discloses an energy-saving type flood early warning method and device for a garage. The early warning method includes the step of
dormancy, wherein before the
water level of the garage reaches a start
water level, the early warning device is in a
dormancy standby mode; the step of working, wherein when the
water level of the garage reaches the start water level, a controller is activated, and the device goes into a working mode; the step of sampling, wherein after the device goes into the working mode, sampling is conducted through a water
level sensor to obtain the height of the water level; the step of early warning, wherein when the value of the water level reaches a threshold value H0, a communication module is started to inform a car owner or related personnel; the step of stopping, wherein when stop conditions are met, early warning is stopped, and the device returns back to the
dormancy mode. The early warning device mainly comprises a base, a digging
rope, a travel switch, a floater, a digital
processing chip, the communication module, a power supply for providing
electric energy and the water
level sensor. The dormancy mode is designed, so the device can automatically switch between the dormancy mode and the working mode; furthermore, an
electronic switch can be arranged for starting and closing a related circuit module, and therefore
energy consumption can be reduced to the greatest extent.