Abstract: Based on the principle of the Kelvin water drop，the idea of applying the high-voltage electrostatic field generated by the water drop to the sewage treatment， is presented in the research.In order to improve the system’s efficiency of oxidization and sterilization，the factors influencing the electrification effect are discussed.We optimize structure of the sewage treatment system according to the experimental data.The experimental result shows that the system is able to oxidize methylene-blue liquid effectively，reflect its capacity for oxidization and sterilization， without any external energy sources，demonstrat its superiority of environmental protection and no secondary pollution.

Key words: principle of the Kelvin water drop, high-voltage electrostatic field, sewage treatment