Automatic liquid-level control device

The utility model discloses an automatic liquid-level control device. The device comprises a pressure sensor arranged at the bottom of a liquid preparation tank for acquiring a hydraulic pressure value of the interior of the liquid preparation tank; a control unit which is connected with the pressure sensor, processes the pressure value returned by the pressure sensor, and outputs a solenoid-valve closure signal if the pressure value reaches a standard set value; and a solenoid valve which is connected with the control unit and responds to the solenoid-valve closure information transmitted by the control unit, the solenoid valve mounted on an input pipe of the liquid preparation tank. The automatic liquid-level control device has the advantages of quick response, small control error and convenient operation, and is simple in structure, easy for production and low in cost, thereby being suitable for popularization.