In order to detect the partial discharge in arresters more efficiently

a model of arrester with the softwarecomputer simulation technology（CST）is established based on the finite integration technique（FIT）. The propaga-tion of ultra-high-frequency electromagnetic waves aroused by partial discharge is simulated. The simulation resultsindicate that the electric field intensity is proportional to the amplitude of the excitation source

and the electric fieldintensity increases as the width of the excitation source decreases. During the propagation

the attenuation of electricfield amplitude is exponential decay

and the initial attenuation speed in horizontal direction is faster than that in ver-tical direction. With the increasing propagation distance

the high-frequency components of the signals also decreasea lot. The impact of environmental medium is reflected in the amplitude attenuation and time delay of electromagnet-ic waves. Furthermore

the results provide a basis that UHF technology can be used to detect the partial discharge inarrester and evaluate the insulating state.