The invention discloses a safety valve, which comprises a valve body, a liquid inlet joint, a spring seat and a reset spring, wherein the liquid inlet joint is provided with a liquid inlet hole. The safety valve also comprises a valve core assembly; the valve core assembly is movably arranged in the valve body and is used for controlling the liquid inlet hole to be opened or closed; the valve body is provided with a liquid discharge hole; the valve core assembly comprises a sliding seat, a screw sleeve and a valve pad; the screw sleeve is arranged in the sliding seat; the valve pad is arranged in the screw sleeve, and is provided with a conical groove; the spring seat is provided with a first lug boss inserted into the reset spring. The safety valve has the advantages that the movable valve core assembly is arranged in a valve case; the valve core assembly can be used for controlling the make-and-break state of an oil path from the liquid inlet hole to the liquid discharge hole; after the valve core assembly leaves far away from the liquid inlet joint, the high-flow-rate overflow can be realized; the flow rate of the safety valve is greatly improved; the axial displacement of the valve core assembly can be reduced through the short-time fast overflow; the axial displacement of the valve core assembly is reduced, so that the axial deformation of the reset spring is reduced; the pressure fluctuation can be finally reduced.