As a very popular dam style, more concrete- faced rockfill dams have been built in the world, but there is presently only a few high CFRDs with dam height more than 100m built on thick alluvium deposits. ChaHaWuSu CFRD with dam height 107.60m and the maximum thickness of alluvium deposits 46.70m, has been built in Xinjiang province, China recently. The excessive of displacement of foundation and dam body may lead to big deformation of peripheral joint and cause the failure of seal materials and produce water leakage. Therefore, 3D finite element analysis was carried out to estimate the deformation of dam. Firstly, 3D mesh including surrounding mountain and alluvium deposits was established by use of advanced grid discreteness technique. Secondly, Desai thin layer elements were adopted to model the interface between the face slab and cushion layer. Moreover, joint elements were adopted to model the joints between the face slab and plinth, plinth and connecting slab, connecting slab and connecting slab, connecting slab and diaphragm wall. Finally, large scales of equations solving method were adopted in the procedure thus the computer calculation time was greatly reduced. The calculation result was compared with the monitored deformation date of ChaHaWuSu CFRD. All in all, the above research will do much benefit to the CFRD design on thick alluvium deposits.