Abstract: Through large scale model test on the seal structure of peripheral joints in the concrete faced rockfill dam (CFRD) of the Shuibuya Project, the following items have been studied: the physical mechanics properties and shape optimization of water stop,the pilot study on copper water stop connector deformations of the peripheral and vertical joints, the water stop seepage control performance and mechanics properties of plastic film,and the water stop structures and their sealing properties of the caulking material and self healing anti-seepage material. Besides, the working mechanism and detailed design of the seal structures are discussed in the paper. The water tight structure of peripheral joints and some measures and schemes for improving design are put forward.