The invention discloses a low-frequency three-dimensional vibration-isolating vehicle seat based on a magnetic negative-stiffness spring design, and aims to solve the problem that a common car seat cannot isolate low-frequency vibrations in a horizontal direction. The low-frequency three-dimensional vibration-isolating vehicle seat comprises a vertical vibration-isolating part and a horizontal vibration-isolating part, wherein the vertical vibration-isolating part comprises a shear type suspension and a zero-stiffness magnetic damper; the shear type suspension comprises a hinged type link mechanism which is connected between a shear type suspension upper part and a shear type suspension lower part; the two ends of the zero-stiffness magnetic damper are separately positioned on the shear type suspension upper part and the shear type suspension lower part; the horizontal vibration-isolating part comprises an upper plate, a rubber damping spring seat, a primary magnet set, an outer magnet set and a seat fixing frame; when the seat bears the vibrations in the horizontal direction, a seat plate connecting plate horizontally vibrates, so that a rubber damping spring horizontally vibrates while a magnet on a bottom plate vibrates relatively; by virtue of the acting force of the rubber spring and a magnetic negative-stiffness spring to the upper plate, the upper plate is kept to have relatively small vibration displacement, and therefore, vibrations in the horizontal direction are isolated.