The invention discloses a magnetic field sensor based on a magnetic torsional effect and a manufacturing method thereof. The magnetic field sensor comprises a piezoelectric material, an elastic layermaterial, a permanent magnet material, a flexible electrode, and an upper surface electrode and a lower surface electrode of the piezoelectric material; the upper and lower surfaces of the piezoelectric material are attached to the flexible electrode and packed between elastic layers as a sandwich structure, the piezoelectric material is in the center of the length of the elastic layer, a pair ofpermanent magnets is bonded to two ends of the elastic layer, the permanent magnet material generates torque under the action of an external magnetic field and generates compressive stress on the piezoelectric material, and the piezoelectric material generates electrical signals for output to sense external DC magnetic field and AC magnetic field. Compared with common magneto-electric sensors, themagnetic field sensor does not require a bias magnetic field, and is simple to drive and low in energy consumption, and the cantilever beam structure based on magnetic torsional electricity also greatly prolongs the service life of the sensor.