The invention provides a 3D printing-based tunnel magnetoresistance accelerometer device with horizontal shaft sensitivity. The device includes a top tunnel magnetoresistance sensing element structure, a central sensitive component structure, and a bottom tunnel magnetoresistance sensing element structure. The central sensitive component structure is formed by 3D printing; the central structure issupported on a base by 3D stereoscopic support beams; and the top structure and the bottom structure are respectively located on upper and lower sides of the central structure and are arranged symmetrically around the central structure. The device adopts the 3D printing instead of a silicon micro-machining process, and has the advantages of accurate size and convenient processing; a sensitive component adopts the 3D stereoscopic support beams, and has the advantages of good reliability, high sensitivity, strong anti-interference ability, and the like, from an aspect of measurement, and the support beams and mass blocks are formed through the 3D printing by utilizing nylon materials, and have better displacement capability in a horizontal direction and better inhibition capability in a vertical direction; and the stereoscopic support beams are arranged by adopting double-layer "U-shaped" beams in an opposite direction, and so, the stability of the sensitive component can be effectivelyenhanced, and the reliability of the device is improved.