A biomolecule magnetic sensor configured to sense magnetic beads attached with biomolecules includes an adsorption pad, a magnetic field line generator and at least one magnetic sensor. The adsorption pad is configured to adsorb the magnetic beads. The magnetic field line generator is configured to generate a plurality of first magnetic field lines, and at least one of the first magnetic field lines passes through the magnetic beads along a first direction to induce a plurality of second magnetic field lines, wherein the magnetic field line generator is disposed between the adsorption pad and the magnetic sensor in the first direction. The magnetic sensor is configured to sense a magnetic field component of at least one of the second magnetic field lines in a second direction. A second shift is provided between the magnetic sensor and the adsorption pad in the second direction.