Underground water mining device

An underground water mining device comprises a water level detector, a roller, a measurement belt, a signal receiving unit and a water pump motor. The water level detector is fixed at one end of the hollow measurement belt which is wound on the roller, the other end of the measurement belt is connected to a wireless signal sending module, a signal transmission line is arranged in the hollow measurement belt, and the signal transmission line is connected with the water level detector and the wireless signal sending module. The signal receiving unit is composed of a wireless receiving module, a single chip microcomputer control module and a DC motor drive module. Moreover, the wireless receiving module, the single chip microcomputer control module and the DC motor drive module are sequentially connected. In use, the water pump motor can be turned on or turned off according to signals detected by the water level detector, so that changes of water level can be effectively controlled in the mining process, and an effective solving means is provided for the underground water excessive mining problem.