Abstract: Leaks in dams are the most dangerous circumstances and easily cause the burst of dams for they run through dams and enlarge rapidly. The use of soft-curtain-unfolding machine can block leaks. The Research Center of Yellow River Flood Control Machines and Tools of Shandong Provice manufactured soft-curtain-unfolding machine. The operation of the machine was demostrated, and it passed the evaluation of the Science and Technology Department of Shandong Provice.