Underground water sampler for geological exploration

The utility model discloses an underground water sampler for geological exploration, and relates to the technical field of underground water sampling equipment, the underground water sampler comprises a gantry supporting seat, one side of the gantry supporting seat is connected with a servo motor, in the underground water sampler, the servo motor is used for driving a wrapping roller to convey a sampling cylinder into a sampling hole, a controller is used for starting a single chip microcomputer, and the single chip microcomputer is connected with the gantry supporting seat. When the water level rises to be in contact with the water level sensor, the water level sensor sends an electric signal to the single-chip microcomputer to enable the single-chip microcomputer to close the first storage battery which is opened in advance, and then the single-chip microcomputer starts the storage battery to enable the electromagnet to generate magnetism to attract the plugging block to vertically move upwards to open the