Taking the island and tunnel project of Hongkong-Zhuhai-Macao Bridge as an example,we introduce the foundation design of immersed tunnel of the west artificial island.Aiming at the problem of the settlement calculation of rigid pile composite foundation under special conditions,we revise the improvement coefficient of composite modulus in the reinforced area of rigid pile based on load test and JGJ 79—2012 Technical Specification for Building Foundation Treatment,propose the settlement calculation method of rigid pile composite foundation under complex working conditions,and compare the results of proposed method with the above specification,relevant reference method and the field measured date.The results show that the proposed method is reasonable and feasible.It can provide the references for the similar projects.