Abstract: If there exists shelter embankment at the water intake area of a power plant, the back silting at the place of intake and intake canal etc. must be solved before the construction of the power plant. Based on field data, the wave field, tidal current field and sand concentraction at the sea area of Shahuan site of the third nuclear power plant of Gangdong province, were analyzed. Combined with the characteristics of the layout of water intake canal and its related water area were carried out. The results expressed that the water inlet will not result in increasing the back silting of intake canal.