Through the research on settlement of Jishixia dam before and after immersion in construction period ,the paper obtained the deformation law in natural state of dam and during immersion period. It also analyzed the settlement of actual measured of Jishixia CFRD and compared with Gongboxia dam. Results showed that the dam deformation monitoring instruments is normal; the dam measured settlement distribution law is reasonable, the maximum settlement is less than 1% of the feasibility study report. The final conclusion is that compared with Gongboxia dam, the late Jishixia deformation is very small and dam settlement convergence rate significantly accelerates.The immersion accelerates dam settlement and the deformation effect is significant.