A magnetic field sensing device including a magnetic flux concentrating module and a plurality of vortex magnetoresistors is provided. The magnetic flux concentrating module has a first side, a second side, a third side and a fourth side, wherein the first side is parallel to the third side, the second side is parallel to the fourth side, and the first side is not parallel to the second side. The vortex magnetoresistors are disposed beside the first to the fourth sides. The vortex magnetoresistors have a same pinning direction. The pinning direction is inclined with respect to the first side and the second side. The vortex magnetoresistors are configured to be connected to form a plurality of different Wheatstone bridges, so as to sense magnetic field components in a plurality of different directions, respectively.