The invention belongs to a high-pressure oxygen check valve. The high-pressure oxygen check valve comprises a valve body; a valve flap is arranged inside the valve body and provided with a valve flap cover; a valve rod is arranged inside the valve flap cover, the top of the valve body is connected with a valve cover with a filling through hole, and the valve rod penetrates the filling through hole; a filing cushion, PTFE (polytetrafluoroethylene) fillings and fillings are arranged between the valve rod and the filling through hole of the valve cover; the side surface of the valve cover is fixedly provided with an organic glass plate; the upper end of the valve cover is provided with a pressing plate, the valve rod penetrates the through hole of the pressing plate, and the pressing plate is fixed onto the valve cover; a pressing sleeve is arranged between the pressing plate and the valve cover and sleeves the valve rod; the upper portion of the valve rod is provided with a double-open connecting sleeve which is connected with the valve rod in a fastening mode; the upper portion of the organic glass plate is connected with a flange, the organic glass plate is connected with the valve cover through a bolt and the flange, and the flange is connected with the valve cover and a high-pressure air cylinder. The high-pressure oxygen check valve has the advantage that, by means of the fully-closed structure of the organic glass plate, moving parts such as the valve rod can be closed completely, and the possibility of burning and explosion due to the fact that impurities enter a valve cavity can be effectively avoided.