Automatic underground water pump switching device

An automatic underground water pump switching device belongs to an underground water pump control device and comprises a power supply unit. The switching device is characterized by further including a water level detector, a contactor and a relay, an output end of the water level detector is connected with the relay, the water level detector and the relay are connected with the power supply unit, a contact of the relay is connected in series with the contactor between a main power supply and earth, and a contact of the contactor is connected in series onto a water pump main power supply circuit. The automatic underground water pump switching device can automatically monitor water accumulation of a drain point, is equivalent to having one person on guard of every water pump all along due to the fact that the device automatically opens a pump for drainage when water level reaches a set high water level, and automatically closes the pump when the water level reaches a set low water level, and can completely elim