A magnetic field sensor, comprising a suspending mass block, a group of Y direction displacement sensors, a group of Z direction displacement sensors and a power supply; wherein the mass block, the Y direction displacement sensors and the Z direction displacement sensors respectively comprise a plurality of metal layers and a dielectric layer between two metal layers. In the mass block, a region corresponding to the Y direction displacement sensors and a region corresponding to the Z direction displacement sensors respectively comprise at least two metal layers connected by a via. The Y direction displacement sensors include two electrodes, each comprising at least two metal layers connected by a via; the Z direction displacement sensor includes two electrodes, each comprising at least two metal layers connected by a via; and the power supply provides a current flowing through the mass block selectively in X or Y direction.