Abstract: The deformation of centrifuge modelling of piled embankments is closely related to the test process. The characteristics and mechanism of settlement and sectional deformation of composite foundation at each testing stage are investigated by the laser ranging method and the image analysis method. The results show that it is impossible to eliminate the deformation of the composite foundation itself during the filling stage by preparing the model under 1g and adopting the method of increasing the centrifugal acceleration to simulate the embankment surcharge. Therefore, the settlements of the foundation during the filling stage and the final settlement are both overestimated in the tests. The foundation rebound is shown at the centrifugal deceleration stage and placement stage under 1g. As a result, the settlement near the centerline of the road will be underestimated, and the horizontal displacement at the slope toe and the uplift outside the slope will be overestimated based on the measured deformation after the centrifugal tests. This study may enrich the understanding of centrifugal deformation process tests on piled embankments.