The contact behavior between concrete face slab and dam body is important to the safety of concrete-faced rockfill dams. The deficient of dam body and the separation of concrete slab from cushion layer during construction and in operation are the main concerns. This paper proposes a contact analysis method to study the effect of non-linearity and time-dependent deformation on the separation and the deficient. This contact analysis method regards dam body and concrete slab as two independent deformable bodies. These two deformable bodies follow Coulomb friction law at contact interface when they contact each other. The rockfill materials in dam body are assumed to be non-linear and time-dependent but concrete slab is elastic. As an example, a high concretefaced rockfill dam of Tianshengqiao-I in China is numerically analyzed, and the numerical results are compared with in situ measurements. The results reveal that whether the deformation of dam body is non-linear or time-dependent, this contact analysis method can effectively simulate the separation between concrete slab and cushion layer without the drawbacks of interface element methods.