Abstract: The simulation of basin excavation process of the sheet-pile wharf in the centrifugal modeling tests is mostly carried out under 1g. Also an elevation of 1g to Ng is added compared with the prototype, which results in the same stress state but different stress paths. The first four-axis robotic manipulator of the Mainland of China has been successfully developed and applied to the 400 gt geotechnical centrifuge at Nanjing Hydraulic Research Institute (NHRI). This robot, with four degrees of freedom, can achieve movements simultaneously in linear directions of x, y, z and rotation of θ. The robot and special tool are used to simulate the excavation of layered soil of the sheet-pile wharf basin under 50g in accordance with the model similarity criterion totally. By comparing the bending moments and the horizontal lateral displacements of the wall got from floor 1g and 50g excavation simulation, the result reveal that the change rules of the bending moments of the wall are basically identical. However, the bending moments of the front wall by means of the excavation are clearly larger and the bending moments of the anchor wall are smaller. The lateral displacement of the wall is greater under floor excavation of 1g.