The invention discloses a fully-automatic earth pillar leaching experiment device. The fully-automatic earth pillar leaching experiment device comprises an automatic constant head height solution outflowing device, a detachable earth pillar body and an automatic continuous sampling device; the automatic constant head height solution outflowing device consists of a target pollutant solution containing bottle and an automatic constant head height mechanism, and the automatic constant head height mechanism consists of a magnet, a valve, a rotating wheel, a bracing wire and a buoyancy ball; and the automatic continuous sampling device consists of a sampling plate, a motor, a relay, a power supply and a timer, the motor is connected with the power supply by the relay, the timer is connected with the relay, a plurality of grooves are evenly formed in the circumference of the upper surface of the sampling plate, a first liquid level probe and a second liquid level probe are arranged in a test tube, the first liquid level probe is connected with the relay by a conductive wire, and the second liquid level probe is electrically connected with the relay by a hard conductive wire, a touch type chute and a conductive metal ball. The fully-automatic earth pillar leaching experiment device has a simple structure, is reasonable in design, convenient to use and strong in automation, saves labor force, and is applicable to popularization.