Automatic-control emptying safety valve

The utility model relates to an automatic-control emptying safety valve which comprises a valve body (1), a valve element (2), a reset spring (3) and a seal ring (4). The automatic-control emptying safety valve is characterized in that an air inlet (5) is formed in the side wall of the valve body (1), the air inlet (5) is communicated with the inner wall of the valve body (1), the reset spring (3) is arranged in the middle of the valve element, upward acting force is exerted by the reset spring (3) on the valve element (2), therefore, the bottom of the valve element abuts against a valve seat of the lower end of the valve body (1), and the valve element (2) can move up and down along an axis of the valve seat. Negative pressure produced when the emptying safety valve conducts emptying operation enables the valve element to move downward, and air enters a pipeline through the air inlet of the valve body. Liquid flowing reaches a balanced state, and the emptying operation is smoothly conducted.