Hydraulic-controlled rotary weir gate is a device used in hydraulic structures such as channels, inlets, outlets, and water engineering facilities (such as diversion wells, regulating reservoirs, etc.). It is driven by hydraulic means, causing the weir plate to rotate around the axis by an angle equal to or less than 90 degrees. This device is employed for shutting off or opening water flow, adjusting water levels and flow rates, and preventing backflow.