The blade seals of turbines manufactured in early years in China have mostly used λ structure. However, the phenomenon of seal failures was widely found in the operations of most domestic units, which shows that this sealing form does not meet the requirements of long-term reliable operation of hydro-turbine units. After a long period of technical research, Techemer Composites has screened out the elastic-plastic polymer alloy with low friction coefficient, high mechanical strength, oil resistance and water-resistant medium of long service life, and designed V-shaped combined sealing structure, which has solved such problem for many power plants at home and abroad. At present, we have successfully solved the problem of long-term leakage in many China’s large-scale power plants using axial flow propeller turbines and bulb tubular turbines.