Bio-clogging is a novel technology in soil seepage prevention and consolidation, and this technology was applied in 3 bank sections of Dawa Reservoir in Chuzhou, Anhui Province. Bacillus pasteurii was chosen as the agent to generate carbonate ions, which could precipitate with calcium/magnesium ions to clog pores and fractures inside the earth bank. In these applications, inside water heads were monitored using installed piezometers and the flow rate of leakage was also measured. Results showed that the reduction rate of the bank soil conductivity can reach 99% in a short time. The whole process of in-situ test can be divided into three main stages: 0-80 h is the development period of bio-clogging; 80-120 h is the peak period and then followed by the tailing period. The soil conductivities were around 10^-5-10^-6 cm/s after bio-clogging treatment, meanwhile the soil strength increased by 13% according to UU tests. Samples inside of the pores were detected using electronic microscope and EDS detector, and main composition was proved to be calcium carbonate.