The invention relates to a safety valve. The safety valve comprises a valve body, a valve sleeve, a control piston, a valve core and a pressure adjusting assembly, wherein an inner cavity is formed inthe valve body; the valve sleeve is in threaded connection with the lower end of the valve body; a valve sleeve through hole which runs through axially is formed in the valve sleeve; the valve sleeveis provided with a first port and a second port; the control piston is arranged in the valve sleeve in a sleeving way; the valve core is arranged in the control piston in a sliding way and can control on and off of the first port and the second port; and the pressure adjusting assembly is used for controlling the opening pressure of the valve core. The safety valve is simple in structure and compact in volume and can realize a bidirectional safety protection function.