Abstract: Based on the microwave biological effects, the mechanism of electroporation, and the theory of electromagnetic, a λ/4 coaxial resonant structure of microwave sterilization is simulated and analyzed with CST software in this paper The results of simulation indicates that when the input power reaches 100 W, the amplitude of the E-field in the area of sterilization will attain 106 V/m. So the cell of virus will be punctured; and the air can be sterilized fast.