Based on Duncan-Chang E-B material model and aimed at the effect of staging impoundment and wetting deformation in practical application，the paper analyzed an rock-fill dam with asphalt concrete core by the finite element software ABAQUS.It contrasted horizontal displacement，vertical settlement and the size of principal stress of dam body with core respectively based on dam，s strain stress characteristic under the one-time impoundment，considering the humidification one-time impoundment and by-stage impoundment.The results show that staging impoundment has little effect on the stress and deformation of dam body and core，but humidification has large influence on the deformation and stress of dam body and core so its effect should be considered in calculation.