Abstract: In order to consider the effect of liquid sloshing in an annular water tank on mechanical performance of a two-stage variable damping TMD， taking an actual high-rise structure as an example， a global model considering the water tank as a particle and the liquid-solid coupling model of the water tank under the full water state and the non-full water state are established by ABAQUS software. The seismic responses of the two-stage variable damping TMD under different liquid-solid coupling states are compared and analyzed. The results show that the amplitude and maximum damping force of the two-stage variable damping TMD considering liquid sloshing are larger under larger seismic excitation， and the sloshing effect of liquid inhibits the full development of the second-stage damping energy consumption of the two-stage variable damping TMD. With the increase of seismic excitation， the maximum base shear force of the liquid-solid coupling model is larger than that of the particle model， and the relative increase amplitude increases accordingly.