Novel self-feedback overpressure cutting device

The invention provides a novel self-feedback overpressure cutting device. The device comprises a valve body, a valve cover, a piston, a valve element combination, a valve element seat and an outlet connection. A drainage channel is processed in the valve body, circular grooves and four inclined holes are processed on the valve cover, the conveying pressure of medium is fed back to the upper end face of the piston, when the pressure exceeds the limit, the piston produces thrust to push the valve element combination under the pressure of the medium, a shear pin is cut through, and the air resistance under the piston along with the air is discharged and disappears through a cavity formed by an exhaust vent on the valve body and four bosses on the valve cover. According to the difference of pressure limiting values, the shear pin can be designed into pins with different materials and diameters. The circular grooves are processed at the end face of the valve element, rubber is vulcanized and cemented on the circul