A bidirectional fluid-structure coupling model between tuned liquid column damper (TLCD) and support structural platform (SSP) was developed to study effects of TLCD-SSP mass ratio and tuning ratio on reducing SSP vibration. Laboratory experiments of TLCD interaction with SSP were conducted to validate TLCD-SSP coupling model. Good agreements between numerical results and experimental data are obtained. TLCD/SSP mass ratio increases from 1% to 3%, the maximum amplitude of SSP upper displacement decreases from 43.77% to 78.32%, and the upper acceleration damping rate increases from 43.26% to 77.88%. There is a phase differences between dynamic water pressure offered by sloshing inside TLCD and upper displacement curves, and the damping energy dissipation effect is maximized when the hysteresis phase difference reaches π/2. The larger mass ratio is more effective in suppressing the structural vibration. But it also brings about a fundamental frequency drift. It is advised that the mass ratio of water in TLCD to SSP should be 1.5%, the total mass of water and shell of TLCD should be about 2.5% of the mass of SSP, and the intrinsic frequencies of TLCD and SSP should be tuned the same so that the vibration controlling performance of TLCD can be improved maximally.