Tuned liquid damper (TLD) is a typical effective passive vibration control device. In view of the problem of lack of research on the damping properties of TLD for high-rise structures in frequency domain under the influences of different parameters, a real-time substructure testing system was established for evaluating seismic performance of high-rise buildings installed with TLD. A series of sinusoidal excitation tests were conducted to investigate the damping performance of TLD with different parameters in frequency domain. The influences of excitation frequency ratio, TLD frequency ratio, TLD mass ratio, structural damping ratio, and input amplitude on the seismic performance of TLD in frequency domain were discussed. Results show that TLD had the best damping effect on structural acceleration and displacement when the input excitation frequency and TLD frequency were both first-order frequency of the structure. Meanwhile, the damping effect of TLD became worse with the increase in damping ratio and was little affected by the input amplitude. When the input excitation frequency and TLD frequency deviated from the structural frequency, TLD did not significantly increase the response of the structure, except for the negative effect when the input excitation frequency was lower than the structural frequency. TLD is more suitable for controlling the resonance response components of structures with small damping ratios, has poor damping effect on the frequency components far away from the natural frequency of structures, and may have great adverse effects on the frequency components less than the natural frequency of structures.