A series experiments were conducted to investigate interaction characteristics of internal solitary waves with a tension leg platform in a large-scale gravity type density stratified tank. Based on KdV(Korteweg-de Vries), eKdV(extended KdV) and MCC(Miyata-Choi-Camassa) theories for internal solitary waves in a two-layer fluid, a theoretical model was established for predicting the internal solitary wave loads on a tension leg platform, Besides the applicability conditions for these internal solitary wave theories were presented in order to apply such a load model. It is shown that the horizontal load on the tension leg platform due to the internal solitary wave consists of two parts which are the drag and inertial forces on the vertical column and caisson, and these two forces can be calculated by the Morison formula, while the vertical load is mainly the vertical Froude-Krylov force which can be calculated by integrating the dynamic pressure along with the bottom of the columns, as well as the upper and lower surfaces of all caissons. A series experimental results show that the drag coefficient in the Morison formula follows some exponential function relationships with the Reynolds, while the inertial force coefficient follows power function relationships with KC(Keulegan-Carpenter) numbers. Moreover, the numerical results based on the theoretical predicting model have good agreement with the experimental ones. This research provides a practical theoretical model based on the series of experimental results for predicting internal solitary wave loads on tension leg platforms.