With the large-scale density stratified tank and the numerical flume proposed, series of numerical cases in line with the experiments are carried out to investigate the interaction between the tension leg platforms (TLPs) and the internal solitary waves (ISWs). The waveforms, and the loads and the torques on the TLP obtained by the experiments and the simulations agree well with each other. Experimental results show that the amplitudes of the dimensionless horizontal force and torque linearly increase with the dimensionless amplitude, while that of the vertical force increases in a parabolic curve. Besides, the numerical results indicate that the horizontal and vertical forces on the TLP due to the ISWs can be divided into three components, namely, the wave pressure-difference forces, the viscous pressure-difference forces, and the frictional force that is negligible. The wave pressure-difference forces are always the major constituents. However the viscous pressure-difference component is unimportant, it is negligible as compared with the vertical forces.