There is a scarcity of research on underground storage tanks, and their seismic behaviour remains inadequately understood. To investigate the seismic response of an underground liquefied natural gas storage tank, a shaking table test was carried out under different excitation directions and spectral characteristics of input waves for various liquid level states of the underground liquefied natural gas storage tank model designed according to a reduced scale of 1/60. The acceleration of the tank, and the dynamic soil pressure, and the hydrodynamic pressure were evaluated through the test. Results mainly show that as the amplitude of the input waves increase, the liquid-structure coupling effect makes the liquid act as a strong damping force, thereby mitigating the vibrations of the tank to some extent. The soil pressure from the bottom to the top first decreased sharply and then increased steadily under each case. The storage liquid was initially manifested as a large fluctuation, and then appeared to be a periodic fluctuation gradually. The long period ground motion has a serious impact on the liquid stored in the underground tank, which will bring significant nonlinear dynamic water pressure impact to the inner tank wall.