The utility model provides a negative pressure
safety valve and negative pressure equipment. The negative pressure
safety valve comprises a valve shell, a
valve seat, a valve element and an elastic piece. One end of the valve shell is used for being connected with negative pressure equipment so that the valve shell can communicate with the negative pressure equipment, the other end of the valve shell is provided with a first through hole communicating with the outside, and the
valve seat, the valve element and the elastic piece are all arranged in the valve shell; the
valve seat and the inner side wall of the valve shell are sealed, and the valve seat is provided with a pressing part. One end of the elastic piece is fixed, and the other end is connected with the valve core; the pressing part is provided with a second through hole, the pressing part, the valve element and the elastic piece are sequentially arranged in the direction away from the first through hole, and elastic force generated when the elastic piece deforms can drive the valve element and the pressing part to be pressed and sealed. The scheme can adapt to negative pressure equipment with different vacuum degree requirements by adjusting the pre-tightening force of the elastic piece, and is suitable for pipelines or equipment needing vacuum during normal operation or work.