The invention discloses a pressure sensor, the pressure sensor comprises: a displacement sensor, a bend pipe and a base; the first end of the bend pipe is fixed on the base, wherein the displacement sensor comprises a first reflective component and a second reflective component, the first reflective component is fixed in a body of the displacement sensor, and the second reflective component is movable relative to the body of the displacement sensor; the body of the displacement sensor is fixed on the base, and the second reflective component is coupled to the bend pipe at a first position of the bend pipe; or the second reflective component is fixed to the base, and the body of the displacement sensor is coupled with the bend pipe at the first position of the bend pipe; when the pressure in the bend pipe changes, the deformation of the bend pipe causes a change in the distance between the first reflective component and the second reflective component, and the displacement measured by the displacement sensor obtains the magnitude of the pressure change.