High-pressure steam safety valve

The invention belongs to the technical field of safety valves, and particularly relates to a high-pressure steam safety valve which comprises a valve body and a valve cover fixedly mounted on the valve body, a valve port is formed in the bottom of the valve body, a ball valve is mounted in the valve port of the valve body, a second through hole is vertically formed in the ball valve, and a third through hole and a fourth through hole are transversely formed in the ball valve. The center line of the third through hole is perpendicular to the center line of the fourth through hole, a fifth through hole is formed in the position, on one side of the fourth through hole, of the valve body, a testing pipe is installed in the fifth through hole, and a sealing unit is arranged between the testing pipe and the fourth through hole. The purpose of the invention is as follows: through mutual cooperation of the ball valve, the closing unit and the test tube, when the safety valve is overhauled, after the ball valve rotate