Abstract: Geotechnical centrifuge model test is an advanced technology to study the key issues of composite foundation. The centrifugal modelling of rigid pile composite foundation under saturated clay condition is complex and has numbers of influencing factors, which should be paid enough attention to. Based on the analysis of the preparation process of centrifuge model of several groups of rigid pile composite foundation, this paper discusses the influence of 1g pile insertion modelling on the shear strength of the foundation model. It is shown that the disturbance of sample preparation of centrifugal model foundation is related to the way of pile insertion, and it is beneficial to reduce the disturbance of sample preparation to guide a hole before inserting the pile. The undrained shear strength of the clay model foundation will be weakened during the molding process under 1g. The comparative analysis shows that the disturbance of pile insertion and the model preparation under 1g are the main reasons for the strength loss of the saturated foundation model. The reduction of shear strength of upper soft soil of composite foundation is greater than that of the lower bearing layer. The similarity of stress history of the soil samples should be fully considered in the centrifugal model comparison test. An ideal centrifuge modelling procedure of rigid pile composite foundation is proposed, which provides an important reference for improving the refinement level of geotechnical centrifugal model test.