The hydraulically controlled one-way valve is a valve that can reverse the flow of the one-way valve by controlling the fluid pressure. This kind of valve occupies an important position in the hydraulic support equipment of coal mining machinery. The difference between the hydraulic control check valve and the ordinary one-way valve is that there is an additional control oil circuit K. When the control oil channel is not connected to the pressure oil, the hydraulic control check valve works like an ordinary one-way valve, and the pressure oil It only flows from the oil inlet to the oil outlet and cannot flow in the opposite direction. When there is control pressure input in the control oil line, the piston ejector moves to the right under the action of pressure oil, and the ejector pin is used to open the one-way valve to connect the inlet and outlet oil ports. If the oil outlet is larger than the oil inlet, the oil can flow in the opposite direction.