This experiment used fluorescent pseudomonas as target cell, which was operated 180 s in the PEF of 30 kV, 50 Hz. By observing the difference of the bacteria before and after the disposal by using the TEM, it is found that the cell walls of the treated bacteria were broken, the irreversible perforations were formed on the cell membrane, the cell inclusions and cell fragments were leaked. As a result, the cytoplasm and nucleolus substances flow away and the cell died. By analyzing and discussing the high-voltage pulsed electric fields sterilization mechanism, this paper reveals that the pulsed electric fields sterilization technique can sterilize effectively, which can maintain the food’s quality and reduce the sterilization cost in maximum. This method can be adapted to liquid foods such as syrup, milk, soup stuff and liquid egg, and so on. [The Journal of American Science. 2006;2(2):39-43].