To study the dynamic response of the structure with suspended mass under coupled horizontal, vertical and tilt ground motions, the dynamic equation of the structure under coupled horizontal, vertical and tilt ground motions was derived. A modified method was proposed to obtain the tilt component. Taking a valve hall with suspended mass as prototype, the shaking table test of a 1∶10 scale model was carried out, and the seismic responses of structure under coupled horizontal-vertical, tilt-vertical and horizontal-vertical-tilt when different lengths of steel cable and spring to hang the mass. The results show that, compared with under horizontal component, the damping effect of suspended mass on main structure under tilt component is more obvious. The damping effect of suspended mass on main structure decrease as the length of steel cable or spring grows. When using spring of the same length to replace steel cable, the changes in acceleration and displacement on the top of structure are not big, but the dynamic tension of cable decreases. Thus, when suspended mass is used as damping system, the cable should employ spring or the member with low axial rigidity.