In order to improve the level of automation, precision and information of water quality monitoring. In view of the traditional water quality monitoring (such as, artificial sampling and unmanned ship satellite, etc.) of such problems as low efficiency, high cost and long cycle, unmanned aerial vehicle technology is proposed to replace the traditional water quality sampling method, which makes the sampling method more portable, diversified and authentic. The device consists of unmanned aerial vehicle, hoist device and water containers. In the sampling process, the sampling depth is set to flipping the switch button on the remote control, and then the latitude and longitude are input in the ground station so that the unmanned aerial vehicle can fly to the designated sampling location. Then, the one-button sampling button on the remote control is moved, and the return button on the remote control is moved again to make the unmanned aerial vehicle return automatically. Compared with the traditional methods, this method has the advantages of high security and low cost, and can promote the development of the modernization of hydrological instrument.