Abstract: In order to study the deformation characteristics of caissons buried in sand under horizontal loads, a group of laboratory 1g model tests are carried out in sand foundation. Based on the model tests, the finite element model is established through the software PLAXIS 3D, and the displacements of the caisson cover and the soil pressures at the front side and the bottom of the caisson are analyzed. The results of the numerical simulation fit well with the test ones, indicating that the software PLAXIS 3D can simulate the load and deformation performance of caissons in sand, which may provide technical supports for further researches on the interaction mechanism between cassions and soil.