Abstract: A non-rock site-pile group foundation-safety-related nuclear structure system model is established by using the large-scale shaking table test method to study the seismic response, distribution of internal force and failure of pile-group foundation under nuclear power structures. The soil model in the tests is the uniform silted clay, and the circular laminar shear container is used to take the boundary effects of soil into consideration. The pile-group foundation is composed of 9 piles with a diameter of 10 cm and a length of 200 cm, arranged symmetrically according to 3×3. The actual safety-related nuclear structures are simplified into a three-layer frame-shear wall structure model. The research results show that the main failure mode of the pile-group foundation is bending tensile failure, most of which is located in the depth range of 4~7 times the pile diameter from junction between the pile top and the cap, and damage of the junction is the most serious, where the bending moment is also greater than that at other positions.