Rubber dam is a new type of hydraulic structure compared with steel sluice gate, and made of high-strength fabric adhering with rubber, which forms a rubber bag anchoring on basement floor of dam. Filling water or air into the dam bag, rubber dam is used for water retention. Emptying water or air from the dam bag, it is used for flood release. Rubber dam has many advantages compared to conventional weirs, such as low cost, simple hydraulic structure, short construction time, perfect seismic performance and effect of stopping leading, and low resistance to water flow in flood season.